Is your rent legal? It might not be. Your landlord might be charging you too much, and we want your help figuring that out.

ProPublica and WNYC are investigating how some New York City landlords jack up rents higher than the law allows – and sometimes get big property tax breaks, to boot.

One way landlords do this is by manipulating so-called "legal" and "preferential" rents. (What's the difference? Our FAQ answers a lot of those questions.) These rents are a staple of the New York rental market, but as we reported, they're prone to abuse.

We need your help to determine where and how often this is happening. If you think your landlord is overcharging you, if you think your building should be rent-stabilized but it isn't, or if you're paying a "preferential" rent and seeing big rate increases, please take our confidential survey below.

We're also interested in hearing about any other strange things you may have in your lease — such as bogus confidentiality provisions, which we uncovered in one luxury apartment lease. This provision said that the tenant could not discuss the preferential rent with anyone without the landlord’s written consent. It's a scary-sounding provision, but likely unenforceable if a tenant brings a complaint against their landlord in court. "I want to make this illegal," New York City Council Member Ben Kallos said when ProPublica showed him a copy.