Whether they have climbed in or not is besides the point. There has been a law for years on a person getting jailed if they did such a thing in a Church.
Two years for simple trespass.
If you can't see that Putin is using this to crack down on dissent, well, maybe you need to read up on some Orwell or Solzhenitsyn.
I'm sure there were also laws against dumping tea into a harbor to protest taxation without representation.