Several things that I know from personal experience.
They do not and I mean not take trespassing lightly. The only way to get into the buildings now is to trespass. No guide is allowed to take you in the buildings anymore due to accidents/injuries.
The problem is the buildings are the best part. Houses still full of belongings. If you go and get into these buildings do not take anything with you. Taking radioactive materials outside of the zone is a bigger no no than trespassing.
>>170883I haven't been back in a couple of years but my friends in Russia say zone sweeps are higher than they have ever been. Apparently the Chernobyl horror movie and banning of being in buildings has caused people to come out more now.