So, do these come with manacles or something? Because I can only imagine the kind of lawsuits that will come when someone fling that thing out the window.

All it requires is a disclaimer, for the more litigious nations:

Something like:

"Heavy objects may break things when thrown at them"

OR

"Do not use while being a moron"

Should do the trick.

At 2lbs the world isn't likely to have a load of little Arnie's running around shouting 'I'll be back...'

you could go out and buy some normal weights! These are ridiculous!