Hi gang - I can't comment on other companies, but I can tell you a little bit about Kryptonite. Yoshi has pointed you to the Q&A on our site about the New York State Law that was passed in 1999 which, basically, voided any 'guarantee' offer. Not just on bike locks, but for everything and anything. Because of this law we wouldn't be able to offer additional protection to our customers in the whole state. That just wasn't acceptable! We worked for a very long time with the state and insurance companies to come up with our current offer. If the Kryptonite lock comes with an anti-theft protection offer (yes, we had to change the name of the program, too) it doesn't matter what state you live in - register and you are covered. Folks in NY get an insurance certificate back from us when they register as proof of the policy.
We might be the only bike lock company that is covered in New York state. I do know we are the only one that doesn't exclude messengers with the anti-theft protection offer. We aren't big into exclusion, if you haven't guessed.
Yoshi, I may be reading your last comment incorrectly, but if you have a Kryptonite New York series lock, and have registered for the anti-theft protection offer, your bike is covered in NYC, too.
Hope that helps a little bit.
Donna
Kryptonite