I understand wanting to be the nice guy, but this guy squatted without your permission and he did it on purpose.All red flags.What else is he hiding?

I tear a tab off the box with brand and model number and tacking it/hiding it behind access panels/under sink tacked up. 

That coupled with a slumlord who attempted to hide some major defects in the property convinced me that it probably was a project not worth undertaking for my first one.

:)  It hides odors and stains.Get the oil based Kilz, and be sure to follow-up with your regular paint VERY shortly after so that it adheres properly. 

I have found a house where the bank is paying a preservation company to hide the mold.

I think that you're trying to justify this in your own mind, when in fact you know that if you are hiding the facts from the bank, you are doing something wrong.We are in a new reality where society is looking for people to blame for all these bad loans.

Yes, i've done basic cleaning and tried to HIDE the odors with spray stuff.Thanks,John

I toured the home with interest to buy, but he seller was obviously (in my eyes) trying to hide the sticker.

Perhaps they don't really want to sell the house--maybe it really is being used as a front for a mafia hide-out, LOL!

My tenants only try to hide things.