Is stalling an eviction on purpose not extortion? I wonder if I could bring criminal charges on a person who is known to stall evictions. Not only stalling them when they are finally brought, but initiating them from the get go?

Its unlikely. A person has the legal right to fight an eviction. Without knowing the circumstances its hard to judge. But I don't see any criminal action here. Unless the tenant committed fraud in obtaining the lease no crime was committed.

There is no illegal activity unless they are asking you to give them something, in exchange not to do this. (and even then that is a fine line, of business dealing)

If they are using the law, legally, for their benefit, then that is just a legal right. A person may in some courts extend evictions for months, this is just part of how he law works. And something landlords need to be prepared for, and make sure they document everything well and do proper background checks prior to renting

If it were illegal or a crime, then the court would not allow it unless you can PROVE otherwise. Can you?

Some states do, however, allow the courts to impose monetary penalties upon tenants who force landlords to take them to court for eviction.