In a cloud hosting environment, you typically don't know where your data and servers are, and thus you don't know what legal and political pressures they may be subject to. If that means that in practice you are subject to the combination of any pressure that can be applied to any one of the hosting centers maintained by your hosting provider, then "the cloud" indeed would seem pretty unattractive to anyone with politically or socially controversial content.
How is it more or less unattractive than having one's own servers in one's own office? Lieberman and Co would simply have leaned on Mom's Best BGP (r) and Pop's Fastest Packets (r) instead of on Amazon, and the result would have been the same. That's the catch with this here series of tubes - you don't control all of the tubes, even if you're Amazon, or Giant National ISP Co, or Massive National Fiber Plant Co. The server infrastructure is the least interesting part of what happened to WikiLeaks. Nathan