Yep, and as a matter a fact, the auction old timers sure do get a kick out of watching unsuspecting newbs overbid a property (and they are more than happy to help bid them up) thinking that they got a great deal only to find out later that it had a huge lien of one sort or another that came with the property they just bought and wiped out their profits, and then some.

are they trying to get rid of property to unsuspecting investors that want a easy deal?

Them you could move forward with an eviction and filing a judgement against the tenant, hopefully this will stop them in heir next attempt at the next unsuspecting landlord.

Has anyone ever tried to stand outside these places and tell the unsuspecting newbies about the scam?

It’s sounds like you often experience realtors trying to make a quick buck on the unsuspecting investor, but I personally experience the opposite.  

Then they would dump the next batch of houses to unsuspecting buyers, using falsified documentation for their income.

., capital replacements they put off to show better cash flow and now they are trying to put off on an unsuspecting buyer, short sales or foreclosures of buyers buying on lower basis and market rents will take a 6 month to 1 year drop before recovering to previous levels??

They are trying to push assets at market values as an investment "cat in the bag" to a bunch of unsuspecting newbies.

I am seeing/hearing a lot more about rental scams in my area, where scammers will list a unit for cheap and collect fees on unsuspecting applicants.  

Deceiving people, taking gross advantage of unsuspecting or naïve soul out of greed is nothing to brag about, rather it destroys your integrity not only as a dealer in RE but as a person as well.My position has always been to first inform the misguided as to ethical practices.