You can also report to the City the property as a possible blighted property if it's supposed to be abandoned
They may be preparing for adverse possession. See
Legal Requirements for an Adverse Possession Claim to Land
When courts look at adverse possession claims, they apply a four-factor test. To qualify as adverse possession, the trespasserâ€™s occupation of the land must be:
open and notorious, and
exclusive and continuous for a certain period of time.