Footballers can sometimes get a bad rap for their behaviour on the field.
Diving, faking injuries and arguing with referees are, unfortunately, all part of the game. But there is an uglier side.
The modern game is less tolerant of players intent on bending the rules, and while referees now enforce the game with a more strict and literal use of the rules, that doesn't mean that some players don't try.
And when they can't let their aggression out on the field of play, some players deem it necessary to release their pent-up energy off the field.
Here is a look at 20 players who you wouldn't want to meet in a dark alley, let alone on a football pitch.
The Swede, renowned for having a short fuse, has had his fair share of negative press attention for wreckless behaviour in matches.
He is a player whose hard tackling and intense approach to the game has meant him getting in trouble over the years. His giant 6'5" frame has clattered into many an opposition player.
Ibrahimovic also holds a black belt in Taekwondo.
It is true that Didier Drogba can sometimes go down too easily: if too easily is hitting the deck when another player's shoelaces brushes past him.
His diving antics are well known, but they are of his choice.
The truth is, there are not many bigger or stronger players in world football today. At 6' 2" and 185lbs, most of which is muscle, Drogba is not a player that many want to tangle with on the field.
Nemanja Vidic is a typically strong central defender. He stands tall at the heart of the Manchester United defense, and never shies away from challenges or confrontations.
His no-nonsense tackling is something that strikes fear into most opposition. The big Serb is not a player to be taken lightly.
Ben Thatcher will always be remembered for his sickening challenge on Pedro Mendez in 2006.
The two players were running for a 50-50 ball during a Premier League match, when Thatcher raised his elbow into Mendez's face. Mendez was left unconscious by the shocking tackle, and needed oxygen pitch-side to aid his recovery.
Thatcher was suspended for eight games by the F.A.
If Ben Thatcher ever suggests a friendly kick around at the local park, his friends should think twice.
Paul Scholes is regarded by many as one of the great players of his generation. There have been times in his career, however, when the red mist has descended.
Scholes has always been a hard tackler, sometimes too hard a tackler.
When matches get tight, Scholes has had a tendency to make dangerous and all-together wreckless challenges to win the ball. Two-footed challenges have been all too common from the midfielder over the years.
In total Scholes has received over 90 yellow cards and 4 red cards in his career-to-date. Not a player who you would want to anger.
Manchester City's wonderkid recently complained about his treatment in England.
"Why always me?" read a shirt that Balotelli revealed after scoring in a match. There are a few reasons.
Stamping, kicking, throwing darts at youth team players, are just the beginning. Training ground bust-ups with fellow players have aslo been reported.
Most recently, against Tottenham in the Premier League, Balotelli surrounded himself in controversy as replays showed him to stamp on Spurs' player, Scott Parker. He received a four-match ban for the incident after the game.
Balotelli has picked up a total of 20 cards in his career for Manchester city so far.
The Brazilian has been far from squeaky clean in his career, but the moment of madness that most will remember was his sending off against the Netherlands in World Cup 2010.
A straight red followed his stamp on Arjen Robben's leg in the tournament's quarter-final encounter, something that has made him a very unpopular man in Brazil.
But that wasn't the end of the story. After the match, whilst giving an interview, Melo angered fans even more.
"If i meant to hurt him, he would have left the pitch. I have enough strength to break his leg," claimed the hot-headed Brazilian.
Diouf's behaviour has sometimes been nothing short of appalling.
Most recently Diouf taunted QPR player, Jamie Mackie, as he lay on the pitch with a broken leg.
"**** you and **** your leg," Diouf is reported to have shouted at Mackie as he writhed in pain.
"I think for many years I think he’s been the ‘gutter’ type of boy. I was going to call him a sewer rat, but that might insult the sewer rats. I think he’s the lowest of the low," said Neil Warnock after the incident.
Andy Carroll, now of Liverpool FC after a £35 million move in January 2011, has been in trouble on and off the pitch.
The 6' 3" 23-year-old has been in a fair few scuffles on the pitch, but it is his off-pitch antics that have earned him his reputation.
Famous for getting headbutted by Zinedine Zidane in the 2006 World Cup, Marco Materazzi has earnt himself quite a reputation for dealing out his own violence.
The Italian Veteran has amassed more than 60 yellow cards and 25 red cards in his career. His aggressive style of play has seen him get in trouble on a number of occasions.
Weighing about 200lbs and standing 6' 4" tall, Materazzi is no lightweight.
Czech player, Tomas Repka, has picked up 18 red cards, 95 yellow cards in his career and has also been involved in incidents off the pitch.
He is reported to have been at the centre of a brawl at a junior football match in which his son was playing. According to witnesses, Repka's wife began swearing at a child who had fouled her son, Tomasso. Tomas Repka then got involved physically.
In 2007, whilst playing for Sparta Prague, Repka assaulted match officials and a TV cameraman after a match. His actions lead to a two-month ban from the game.
In 2008 Repka was sent off in the first minute of the match against FC Brno in 2008.
If the rumours are to be believed, Pepe could be playing in the English Premier Division as soon as next season. He has been linked with a move to Manchester City in a possible deal involving David Luiz.
But would he be welcomed in England with his tarnished reputation?
Most recently, Pepe has been in the spotlight for stepping on Lionel Messi's hand in a match between the Spanish giants, Real Madrid and Barcelona.
He managed to escape punishment for that incident, but he was not so lucky when he kicked and stamped on Getafe player, Javi Casquero, in a La Liga match in 2009.
The defender received a four-match ban for his disgraceful actions.
Steven Gerrard is adored by Liverpool fans for being intense and holding nothing back. Although he has had a few scrapes in matches, it is his off-field behaviour in particular that has given him a reputation.
In 2008, Gerrard was charged with assault after brawling on a night out. The fight was caught on CCTV although the charges against the player were eventually dropped.
Before that, Gerrard was reportedly involved with some shady characters on Merseyside. He was thought to have hired John Kinsella, a boxer and martial arts expert, to take care of Liverpool gangster, George Bromley Jr.
A giant of the game. Manchester City's right back is perhaps one of the strongest players in world football today.
The England international weighs in at an athletic 183 lbs, most of which is pure muscle. The way he throws himself around the field means that other players generally try to avoid the man-mountain.
He has recently been involved in a training ground altercation with Mario Balotelli, but other than that he is generally a well-behaved player. To call him a gentle giant is perhaps a little too kind.
The German goalkeeper always seemed to be at the centre of any on-field drama when he played for Arsenal.
Lehman has been known to use his physicality to get the better of players. He has pushed, shoved, kicked and stamped his way onto this list.
Since leaving Arsenal, Lehmann has stamped on a player in a Bundesliga match and stolen a fan's glasses after being asked, 'why can't you just be normal, Jens?'
The Manchester United player's temper has always been his Achilles heel.
The striker has always been a passionate player, but his passion has been known to spill over and become something more sinister at times.
Whether or not there are television cameras focussed on him, Rooney will kick, headbutt, stamp and swear at his opponents, if something upsets him.
The media have branded him a 'thug' and a 'yob' in the past. At times, they might not be inaccurate assessments.
This lady became an internet phenomenon after the above video was released of her unique match tactics.
The University player, competing for New Mexico Lobos, is shown to commit a number of clear fouls, punch a member of the opposition in the back, pull another down by her pony tail and forearm another competitor in the face.
Although she was only yellow carded at the time, Lambert was later banned from using any of the universities athletic facilities or from participating in any of their programs, after the video came to light.
"I am deeply and wholeheartedly regretful for my actions," said Lambert in a statement.
She may have been remorseful when she heard of her punishment, but it certainly didn't look like she was when standing over her floored opponents.
The bad-boy of English football, Joey Barton has been involved in controversy on and off the field.
In 2004 he stubbed a lit cigar out in teammate Jamie Tandie's eye at a Christmas party. He was punished and subsequently promised to improve his behaviour.
Since that time, he has broken a pedestrians leg by hitting them with his car, been involved in a training ground bust-up with Ousmane Dabo and has been arrested for assault, among other misdemeanors.
It is clear that Barton has a dark side, and that it should be avoided.
Ex-Everton player Duncan Ferguson was, apparently, not a man to be messed with.
On the pitch Ferguson was a very physical player to say the least. Eight red cards in his Premier League career equalled a record for the most sending-offs in England's top flight.
Off the pitch, an incident showed that the 6' 3" Ferguson was not to be underestimated by anybody. Ferguson managed to detain a man after he burgled his home in 2001.
The man spent three days in hospital as a result.
His nicknames over the years have included, 'Big Dunc,' and 'Duncan Disorderly,' the latter name relating to his four convictions of assault.
The fearsome Gatusso is loved around the world for his aggressive style of play and hard tackling.
To say he has a short fuse is a little generous, the man has no fuse.
The rough-looking Italian has a temper, and it has boiled over on more than a few occasions.
Youtube is swamped with compilation videos of Gattuso's tackles. They are almost funny until you think about what it would be like to be on the receiving end of one of them.