The same thing regularly happens with boats. A boat may be needed to be moved for a host of reasons, at the jetty/dock to retrieve or launch other boats safely or when it’s dragged anchor. Some whinge and some don’t. Just another day in the boating world.
If you so much as jump onto a boat at our local pier without permission you will most likely get a visit from the local constabulary. Heavily monitored by CCTV on most bayside berthing piers in Melbourne and the owners don't take lightly to un-welcomed visitors, let alone you try to move someones parked boat. Now if you left a boat unattended at a launching ramp or such it's more fluid, especially if the vessel is creating a hazard to navigation, however you'd still be at a lot of legal risk by handling someone elses property without permission. But a private vessel parked in a legal area out of movement areas, nope, not a chance the owner will laugh it off. It would be no different if someone parked across your driveway and you took matters into your own hands and hotwired or rammed the car out of the way, rather than call the authorities to remove it.
Simple fix, buy a wheel clamp or two, no-one can roll your craft away then.