The landlord of rent-controlled apartment building in San Francisco reportedly sent a letter to residents that they have to make $100,000 per year to live there, and prove it.

Citing a blog that posted the letter, The San Francisco Chronicle reported that the unidentified landlord of the Lower Haight neighborhood building may be having an ongoing battle with tenants. But some say the landlord’s alleged tactic is illegal.

"They certainly cannot evict anyone if they do not meet their income requirements," Sara Shortt, the head of San Francisco's nonprofit Housing Rights Committee, told The Chronicle.