I was also curious about this. a bunch of BASE jumping hats dropping off a building is exactly the sort of project I would momentarily think about doing and never seriously entertain due to being certain that sooner or later someone, somewhere is going to sue me for some marginally harm-like side effect.
I don't know how litigous your region is but of all the people you know who have been sued, how many of them got sued for something silly vs a more low effort scheme like the classic throw yourself onto someones car and have 'back pain'? You might be safe to do silly shit on the basis that there are easier and better targets available.
