Logan Square landlord evicts tenant for flying Palestine flag
Logan Square landlord evicts tenant for flying Palestine flag
chicagoreader.com
No evictions—or movie tickets—for solidarity with Palestine - Chicago Reader

The scumbag also owns the Logan Theater.
Yeah, that's not legal. Hope the tenant finds a good lawyer.
One of the high-points in my life was having a landlord show up with the local sheriffs to try and force an eviction that up until this point had only been verbal. I happily showed them the state's tenant laws that said "30 days after written notice is provided" and had a lawyer friend on speed dial if they had any questions. Landlord got so belligerent that the sheriffs escorted them off instead.
Also a PSA: If you rent, know your rights.
Sounds like he'd have to go through a judge first too.
True, at the end of a ten day (or 30 day) notice, the landlord can go to court to force the tenant out. This process will take a while, but it will immediately blacklist the tenant and make it much harder for them to find a new rental.
So in practice, it's often better to leave before the landlord goes to court.