I like the "Am I Dating a Cat Murderer" group idea. I can hear the news clip now:

Small-time detectives working together on a Facebook group called Am I Dating a Cat Murderer aided police in discovering the identity of ______, the infamous serial killer. Formerly accused of being a bunch of paranoid schizophrenics, the group is now lauded for their devotion to their feline companions and their suspicion of...everyone.