I've heard that they can be picked with the fingernail...is that true?
So, remember that I am asking if they can they picked with the fingernail. It's a problem related to the locking mechanism, not the strength of the cable itself. Yes, I know cable locks can be easily sliced through with bolt cutters, but that's not the problem we are discussing on this thread.

Who makes the lock?... really Basic cable locks are usually Cut, not Picked.

And if you want to destroy the locking mechanism, it's easiest to use a dremel or some such tool, on batteries.

No lock is unbreakable. But thieves tend to specialize, and often just go for one kind of lock.

I don't know about picking, but I can cut one with pliers in about 10 seconds.

I've tried to pick my cable lock with the tip of the key and fortunately it didn't work. It's not quite a basic cable since it is 1,5 meters(5 feet) long and has a thick polymer coating(not sure if it's plastic or rubber).

there are too many brands and models of cable locks to just generalize them. as others have stated, most thieves will probably cut the cable before trying to pick the lock.