That and there seems to be some kind of weakening with their tabs over time. Fresh ones are always easy to remove, but ones that I've had up for a year or two seem to have the pull tab snap off much easier, you really gotta be ginger with those fuckers.

When I used to work in some dorms at a college they forbid them too, because every semester after move out almost every room had five to thirty some leftover command hook attachment plates still on the walls because the tabs snapped when they tried to get them off and hey their parents will just pay the fee for an uncleaned room.

I will say though, a credit/library/whatever card is your friend there. In my experience, squishing the command strip down like an accordion underneath the clear plate seems to work as well as stretching it out in terms of getting it off without taking chunks of the wall out.