That would be like wearing a shirt with a bullseye on the front and back and the words "Shoot me here." The only place dumber to use would be a cloud service run by Putin and his oligarch buddies!

Personally I don't view any cloud as safe for storage of anything I own. I only use a cloud to store info I want to sync between devices, and I'm very careful that none of that info is a security risk. If I want to transfer a file from one device to another I either do so via cable connections are occasionally I temporarily place a file on my personal website to be able to transfer it, but I don't do the latter very often.