I don't think that's true, given that Amazon is a US-based company -- so they can be compelled to turn over data as a result of the Patriot Act, etc. Microsoft admits this is the case with them and I suspect it's true for other cloud providers as well.
This. Having worked for a few multinationals, I know that any US-based business is subject to the Patriot Act, no matter where their servers are located. Obviously they could choose to refuse access, if they really want to experience Guantanamo's tropical weather, but chances are that Interpol agreements will find a way to get that data anyway. Also, as soon as data enters your US-based network they can tap it, which makes your hosting arrangements irrelevant as long as you have US-based clients. The only practical difference is whether relevant US authorities can just show up at the facilities and get cracking or not.
Besides, it's all pointless anyway; any mainstream business (a category including any mainstream cloud provider) wants to be on the good side of the US government, so they'll bend over backwards at the first occasion.
http://www.zdnet.com/blog/igeneration/microsoft-admits-patri...