When you expose a scammer, they don't learn their lesson unless they go to jail. They just find a new way to do it. Agencies that charge fees are now established to be evil thanks to the good people at Preditors and Editors and many other organizations, but that doesn't mean people aren't after your money and will find a way to get it.
Recently my agency received a letter that was a promotional pitch for a service by a company that would provide us with (for a very small fee, or no fee at all; I can't remember) rejection letters, or even stamps with our agency's name so we could just stamp the rejection line onto the author's query letter. It's essentially free paper and ink, but the catch was that all the rejections would include a link to their website, which coaches people on how to write novels (for $$$). Not only was this preposterous (no agency can't afford to type out one form rejection and photocopy it a bajillion times), it was also a scam - not for us, but the people who got rejected. We didn't dignify them with a reply.
Here's another one:
Rejector, I seek your opinion on:
1) having a freelance editor review/edit your book before sending it out to agents (I write non-fiction, so I'm usually in the "proposal" mode)
2) author representatives who "connect you with agents and publishers." (one i just stumbled on: authoronestop.com) isn't it just as effective to do research on your own, and submit to specific agents who represent your genre?
(1) Having a freelance editor review/edit your book is not a bad idea, provided they are legitimate. To an a normal eye, it is very hard to tell if people are legitimate, or if they are, if they're any good. Follow up on their references and see where that leads, first
(2) Instead of playing scam agents themselves, it seems the trend now is to pretend there's some kind of intermediary between you and an agent, like an agent is an intermediary between you and a publisher. Well, there isn't. We don't generally have people sending us stuff on behalf of new writers unless they are (a) our clients and friends or (b) other agents we know and trust and got drunk with at Frankfurt. I've never heard of Author One Stop.com, which is bad enough sign that I would discourage having anything to do with it.