"One of the largest football survivor pools was shut down this week after federal agents seized documentation and the money the pool organizers collected, sources told ESPN"

ESPN:

Several players of Ron & Mike's Football Pool, who spoke under the condition of anonymity, and had access to the website from the beginning of the season, said there were at least five NFL survivor pools this season with at least $2.5 million at stake to the winners.

...

The two weren't completely covert about their operation. Kroenengold filed to trademark the name "Ron & Mike's" for survival pools in 2011. He received the trademark in 2012.