Bermbits- Hi! Good to see you here!
I don't know of any one who has refinanced online, but, IMO, the caveats would be like any other serious endeavor.
I have responded, on Abuzz, to many qs where people were interested in knowing if a certain company was legitimate. Just putting the name into www.google.com, and seeing what came up, I found a LOT of scams.
Before I would give out ANY personal information, I would check out the company- Call the Better Business Bureau, check out the company's credentials. If they list any references to professional associations, check them out.