You mean, like these desperadoes?
While one of the definitions of gang implies criminal activity, definition 2 is:
a group of persons having informal and usually close social relations [watching TV with the gang]
Hence, there can be non-criminal "biker gangs", in the sense of people who enjoy hanging out together.
Kinda funny that you bothered. TXG8R clearly saw that definition, he or she simply ignored it. I knew that; thus my comments about being ‘coy’ or ‘cute’, and not bothering to take the time to point it out. If someone is intent on being a jerk, no amount of explanation will help. Only those who are intent on seeking truth will see truth.
http://www.mysanantonio.com/news/local/article/Bandidos-caught-in-Hog-Trap-4926531.php