MimeSec was a black hat computer hacking group consisting of cyber criminals that defaced and DDoSed large sites, along with multiple swats including places such as a 15 year old kid that goes by the online handle validate as well as JFK Airport. The groups leaders and most known users go by the online handles Suffix, LinuxPorn, Lucifer, R007ME, and zylren.

Literally everyone, ever. Including the writer of this definition.

A computer hacking group, they have not participated in any of the recently defined activities. They have however done lots of other blackhat computer hacking.