Where you can get in trouble is the following:1) If you write about the complex is defamatory, you could be sued for defamation. Defamation is the public making of an untrue factual statement which puts a person or business in a bad light or damages its reputation. While opinions are not defamation, and nor are provably true factual statements, sometimes it's easy to defame without quite meaning to. For example, say you write "the complext has never closed its security gate at night"--that is a factual statement, and if they can show that they have closed it sometimes, it's false; thus, it would be defamation.2) Even if you think that what you wrote is true--and even if you're right, and if sued would win--if they complex disagrees and can make out a case, believable on its face, that you defamed them, you could end up having to defend against a defamation case. That could be costly, even if you win.3)  In some circumstances, they may also be able to make out a case for tortious interference with business, if you do things that could be construed as harassing their potential tenants.In short, it may be satisying to you to do this, but you could easily be sued.