There are some group rides from time to time, they usually end up with food. Some rides have ended up with pie, bbq, or breakfast.
Here are some past rides:

http://www.bikeforums.net/showthread...ht=boston+ride
http://www.bikeforums.net/showthread...ht=boston+ride
http://www.bikeforums.net/showthread...ht=boston+ride
http://www.bikeforums.net/showthread...ht=boston+ride

Here was last week's pie ride, (I was not there..):
http://www.bikeforums.net/showthread...ght=boston+pie

Alexi was wanting to do another redbones ride soon, maybe this weekend sometime..

Here is the link to alexi's post about a possible redbones bbq ride this week sometime:
http://www.bikeforums.net/showthread...ht=boston+ride

And if by mayhem, you mean ride bikes fast through the city, then yes, I do cause mayhem, and yes, I'd be down to cause some mayhem.