Many NFL teams have a player on their roster who has been in trouble with the law at some point. It's unfortunate but common to most rosters.
This isn't Smith's first incident, and the official Green Bay Packers Twitter account posted a picture of Smith with the question "Where do you draw the line on character?" The included link led to a Q&A with team website beat writer Vic Ketchman in which he talked about how to weigh the risk vs. reward in drafting a player "with some issues in his past."
It's a fair question that was considered thoughtfully by a writer who covers the team rather than serves as a part of it, but it's certainly unusual for a team to send out a tweet like that spotlighting another team's player. Since the article was published, the tweet has been deleted.
Bleacher Report's Matt Miller has a suggestion for San Francisco:
Every team has had to deal with its fair share of questionable characters at some point.