Yeah - security is a relative thing. But I'm also thinking that if anyone can carry and use a 5ft chain cutter in public - it probably wouldn't matter how fast they cut the chain. If bystanders will ignore him for 1 minute they'll ignore him all day. Inside and controlled access is the most effective security.

I think part of the risk is also related to what you own and where its parked. I regularly parked a BMW K1 in front of the street unlocked for years with no issues. On the other hand, one of my buddies had his Harly stolen from inside his private garage were it was locked with a chain - while he was asleep in the house! Apparently they picked the garage door lock and used a torch on the chain. The bike was less than a month so my impression is that the address, make and model were sourced at the dealership.

My comment about the plasma torch was regarding machining. Anything else us too hard on tools and less cost effective.