No one.
Sometimes the law places the whole apparatus of judges, police, prisons and gendarmes at the service of the plunderers, and treats the victim - when he defends himself - as a criminal. - The Law- Frederic Bastiat 1801-1850
Where is law enforcement? What are we paying for in this republic?
These scammers have done this before. They new they could exploit her by taking advantage of the law regarding landlord-tenant disputes. Mind you they were not squatters in the true sense of the word because they were there under agreement (basically a lease). So yes to get them out did require eviction proceedings. As I stated the scammers new this. They probably have made other owners pay to get them out.
I don’t know why overstaying in an AirBnB or such is not treated like overstaying at a hotel/motel/ most likely to satisfy looking zoning codes which prohibit that commercial occupancy. Which means owners are at a risk if they agree to let someone stay in their home. One very good reason to consider carefully whether being a AirBnB host is a good idea after all.
A large fraction of them are routinely harassing honest citizens for fun and profit. And a large fraction of them embody the slang term "pigs" ...