When you hand it off to google it's now on their servers and as their user agreements point out your shit will be scanned and made available to law enforcement upon request and proper authority (whether that's a warrant or just Bill from computer forensics asking for it, I don't really know). When it's on your phone it is not being scanned. It's just like having to get a warrant to rifle through your house for evidence. The same should be required for personal devices. It being digital doesn't mean it should be any less safe than if it was on paper.