What to do if someone has locked their bike to yours?

The guy seemed genuinely apologetic apparently, the way it was locked took serious effort to lock her frame as well so still slightly dubious that it was a genuine mistake.
He got an earbashing from Liz, if he was just a clueless fucking idiot hopefully he learned a lesson. If he was a theiving toe-rag he knows not to fuck with her again...

This is a positive outcome methinks.
I'm still not convinced he's innocent of pre-theft.
I saw a youtube video of a bike thief in a helmet and fluro vest as part of the disguise...

how much dollar is one?

I had a quick look. Starting at a hundred quid. Hitting £150 for a good one. I'd be happy to chuck ten quid in to know that there was this kind of "insurance" available and I'd happily put my name on a list of people to call who were willing to chop a lock off. We'd need guidelines... like maybe we only ever travelled in pairs (at least) and as a forum we had to be convinced of ownership of the bike?

It seems a bit of a mad suggestion but not too crazy.