Earlier quoted context omitted.
The question has never been "Can you trust cloud services?" It's "Can you trust them more than the alternatives?" Yes, you can almost certainly keep your private data more secure in a system you build and monitor yourself(1). Until an NSA or GCHQ-level entity takes interest in you, and uses a 0-day exploit on your system or just physically walks in with a warrant and steals your physical media. How is that functional…
There is a massive, massive difference between automatically slurping all data coming in and out of a cloud provider, and going after somebody with a targeted exploit or physically seizing machines.
grab * -ss 834-29-1293
or whatever they do.