Cloud storage is an incredibly useful technology that makes it easier than ever to keep copies of your files forever. But it also has a few downsides, including cost, the potential for someone to gain access to your account, or the simple fact that you’re trusting a major corporation like Google or Microsoft to keep your data away from prying eyes. And when Microsoft has a list of file types that aren’t allowed on OneDrive, you know the company has at least some access to that information.