New locks required

...the biro/kryptonite lock-pick :
http://www.youtube.com/watch?v=Wl1gsW3KcBU

• couldn't find any using bolt-cutters, they didn't work at all when I tried, but then I'm not the strongest chap on the planet. Some people break the D-locks by putting a length of scaffolding pole in and levering them apart. But if you choose the right thing to lock to then there's no space left in the D to get anything in-between.
  
  

One of the best bits of advice I heard was (fairly obviously) that if you know someone who's had a bike nicked then don't buy the lock they had.

...I sometimes see just locks attached to railings with the 'private property no bikes'etc signs, I assumed caretakers just cut thru the bike and leave the lock as some kind of threat... just paranoia? anyone heard of this happening?