Writer Beware - Agent Scams

We writers are generally a trusting lot.  We want to believe the 'agents' out there are going to represent us, get a sale and we'll both profit. 
And, most of the time there's validity to that hope/belief.  Most agents are legit, trying to make a living, and get downright excited on  many levels when their clients succeed.
But, there are the bad apples in the lot, as there are in any industry, and it's a good idea to know what red flags to watch for. 
Here are a few I've experienced...