What's to stop your developers ripping off your code? They'd probably find it a hell of a lot easier than an Amazon employee, they'd know the prospective value and they could steal it more easily.

What happens if you host your site with a company like rackspace? Would you not do it because of the risk that they could steal your code? When do you stop on this paranoid train? Do you stop your developers from seeing it? Do you stop users from accessing your site since the EU courts just found that functionailty cannot be copyrighted and is therefore open to being reverse engineered?

Personally, I think the risk is a lot less that Amazon will steal you code as the liability Amazon would face as well as negative publicity means there's a lot more pressure on them to keep things secure than there is from internal perspective. I do however know of employees who have successfully ripped code and gone on to produce major businesses on the back of it and they could not be halted or prosecuted because they were individuals. You have a lot more recourse and less burden of proof required between companies.