Per Rovell, there were at least five NFL survivor pools this season under the Ron & Mike's umbrella, and the pools had at least $2.5 million at stake for the winners.
The federal agents who shut the pools down reportedly seized documentation and all money the website had collected.
The pools were run by Ron Kronengold and Mike Bernstein, and those who were still alive in the survivor pools were sent the following message, according to Rovell:
"Please be advised that the Ron and Mike website has been forced to shut down at this time and is unlikely to open again.
"We understand your frustration and anger at this time but closure of the pool is beyond our control. We apologize to those that are still alive in our various pools and we ask for your patience and understanding while we contemplate the next steps. Unfortunately at this time we cannot make any additional comments."
The warrant against Kronengold and Bernstein was reportedly filed by federal prosecutors in the Eastern District of New York.
Per Rovell, it isn't against New York state law to run the pool without profiting, but if Kronengold and Bernstein took a cut of the winnings, charges of bookmaking and profiting from a gambling activity are possible.
Survivor pools are a popular form of NFL gambling in which participants pick one team to win each week.
Once a team is picked, it cannot be selected again for the remainder of the season. A player is eliminated when a team they picked loses, and the winner is the last person remaining when everyone else has been eliminated.