A wee story.
Parked my bike yesterday lunchtime in Edinburgh at top of Middle Meadow Walk yesterday, outside Starbucks/Peters yard, admittedly with a cable lock (know they aren't really suitable locks), and from my window seat in the cafe I see some guy surrounded by his mates trying to yank the bike off the lock/railing in full view, at a busy lunchtime. Probably trying to break either the lock or the little railing. Ran out the door, shouted and they ran off, bike was ok. Own fault for poor locking up.
Lesson learnt, a cable lock is not suitable at all, and use a proper bike railing...
Boring story I know, it must happen more than I know, but I thought the bike would be fine for a quick coffee, with the bike in view, but a cheap lock and slim railing really is an attractive proposition for opportunist thieves!