A friend wrote me a simple question today. My response turned out to be longer than i expected, but i hope it's useful (and maybe other people will have better suggestions) so i thought i'd share it here too:
Angela Starita wrote:
I'd like to save my work in a location where I can access it from any computer. I'm wary of using the mechanisms provided by Google and Apple. Can you suggest another service?
Here's my reply:
I think you're right to be wary of the big cloud providers, who have a tendency to inspect your data to profile you, to participate in arbitrary surveillance regimes, and to try to sell your eyeballs to advertisers.
Caveat: You have to trust the client machine too
But it's also worth remembering that the network service provider is not the only source of risk. If you really mean "accessing your data from any computer", that means the computer you're using to access the data can do whatever it wants with it. That is, you need to trust both the operator of these "cloud" services, *and* the administrator/operating system of the client computer you're using to access your data. For example, if you log into any "secure" account from a terminal in a web café, that leaves you vulnerable to the admins of the web café (and, in the rather-common case of sloppily-administered web terminals, vulnerable to the previous user(s) of the terminal as well).
Option 0: Portable physical storage
One way to have your data so that you can access it from "any computer" is to not rely on the network at all, but rather to carry a high-capacity MicroSD card (and USB adapter) around with you (you'll probably want to format the card with a widely-understood filesystem like FAT32 instead of NTFS or HFS+ or ext4, which are only understood by some of the major operating systems, but not all).
Here is some example hardware:
Almost every computer these days has either a microSD slot or a USB port, while some computers are not connected to the network. This also means that you don't have to rely on someone else to manage servers that keep your data available all the time.
Note that going the microSD route doesn't remove the caveat about needing to trust the client workstation you're using, and it has another consideration:
You'd be responsible for your own backup in the case of hardware failure. You're responsible for your own backup in the case of online storage too, of course -- but the better online companies are probably better equipped than most of us to deal with hardware failure. OTOH, they're also susceptible to some data loss scenarios that we aren't as individual humans (e.g. the company might go bankrupt, or get bought by a competitor who wants to terminate the service, or have a malicious employee who decides to take revenge). Backup of a MicroSD card isn't particularly hard, though: just get a USB stick that's the same size, and regularly duplicate the contents of the MicroSD card to the USB stick.
One last consideration is storage size -- MicroSD cards are currently limited to 32GB or 64GB. If you have significantly more data than that, this approach might not be possible, or you might need to switch to a USB hard disk, which would limit your ability to use the data on computers that don't have a USB port (such as some smartphones).
Option 1: Proprietary service providers
If you don't think this portable physical storage option is the right choice for you, here are a couple proprietary service providers who offer some flavor of "cloud" storage while claiming to not look at the contents of your data:
I'm not particularly happy with either of those, though, in part because the local client software they want you to run is proprietary, so there's no way to verify that they are actually unable to access the contents of your data. But i'd be a lot happier with either wuala or spideroak than i would be with google drive, dropbox, or iCloud.
Option 2: What i really want
I'm much more excited about the network-accessible, free-software, privacy-sensitive network-based storage tool known as git-annex assistant. The project is spearheaded by Joey Hess, who is one of the most skilled and thoughtful software developers i know of.
"assistant" (and git-annex, from which it derives) has the advantage of being pretty agnostic about the backend service (many plugins for many different cloud providers) and allows you to encrypt your data locally before sending it to the remote provider. This also means you can put your encrypted data in more than one provider, so that if one of the providers fails for some reason, you can be relatively sure that you have another copy available.
But "assistant" won't be ready for Windows or Android for several months (builds are available for Linux and Mac OS X now), so i don't know if it meets the criterion for "accessible from any computer". And, of course, even with the encryption capabilities, the old caveat about needing to trust the local client machine still applies.