The Downvoting Coalition was a HUGE group, composed of, you guessed it, downvoters. They were believed to be made up of 85 members total, with even three moderators in their power. It's leader's are unknown, and will probably remain so, forever.
Most of it's members were truthful, however, a few, such as: Dr-L337, AegisReflector, Dancing-is-Forbidden, along with a few others, put the group's secret PM's in the public eye of YTMND, they betrayed the group, and, others eventually found out about them, then the mods, and finally, Max. With this, they suffered a defeat, and it's most powerful members were banned, and taken out.
If this wasn't done, however, and the group stayed in secrecy, YTMND would have suffered a crippling defeat, all sites would've been downvoted, profiles could've been destroyed, and the site could've been in chaos. Their group highly outnumbers the upvoter's clan in power, and size of members, therefore, they would've been the "most-powerful force" to reckon with on YTMND, especially with 3 mods with them.