I use jack stands, always will, however the cribbing blocks I just started using make jack stands look unsafe, quite surprising actually, That guy deserves a Darwin lifetime achievement award.
That exact thing happened in my small town, but in my local case there where 2 guys stealing wheels from the local Ford dealership. One of the guys got crushed and his buddy left him there for dead and went ahead and stole the wheels he had removed. He was eventually caught, what a friend.
I have seen some guy with his car up on 4 sissor jacks! Nothing bad happened but I could not even stand to look long or be anywhere around! stupid, stupid, stupid! I should have snapped a picture but I couldnt stand to keep looking that way.