Nolongerajw
I am in Indiana - rural Indiana. I know of no law against what he did - but I think you should check the options mentioned above.
Seems like $70 is pretty significant increase - was there a change in owners? I know that if you have a lease [and I wonder if 8 years in the same place does not qualify somehow as an 'assumed lease'] there is a requirement that terms of the lease cannot be changed for so long in the case of ownership changes.
Seems like a quick call to the county courthouse or city hall would put you in touch with the right person in your area to resolve rent issues.
Jeff