This is a good example of why I wont let my bike out of my sight if I'm out and about. I'm known to sometimes lock my bike with a really cheap lock + cable that would take a person with a hacksaw about 15-20 seconds. Thing is, it takes me 5 seconds or less to get there. I essentially just use it to keep someone from grabbing it and riding away.
Once I have my next bike, I will probably never leave it unattended at all. Wont let me walk around your store with it? Not buying from you. Have an issue with it in your handicap stall? Oh well, someone else wont.
As for the OP not bashing these guys, I think he did the right thing. They'd have had a lot more money if he'd have been charged with assault & battery and they got whatever cousin vinnie type they could find to sue him. I wish he'd have been able to ask them how they identify each other so they know who the other thieves are. It would be nice to have a method of identifying them.