File Deletion & Cloud Backups + Can You Trust Google?
I actually use Google for a lot of things. The convenience far outweighs the violation of privacy for me. This is because, while I take steps to protect some of my data, I don't really care about privacy for most of my data in the cloud. I don't care if someone reads 99% of my emails--most of my communications are in public forums these days anyway (Twitter, facebook status updates, etc), which have so little privacy it's laughable.
I use Gmail to check and manage all of my email accounts. I have several different servers/accounts with various standards of spam filtering and accessibility (and all with different interfaces). Gmail lets me combine them all into one, adding the best email search and online interface I've ever used.
I used to use Thunderbird, manage meticulous backups myself, port around my latest email repository on a massive thumbdrive. But then I realized something: it's a pain to manage all of my email locally, especially when I want to be able to access it from any machine (or my iPhone). And, at the same time, I wasn't really providing myself any extra security--in fact, I was increasing the insecurity of my email. Here's why:
All email goes through several parties anyway before it gets to you. Even if you manage your email locally, it resides in someone's outbox, their backups, your email server and it's backups + anyone who intercepted it along the way between any of those points. But now that you are managing a local copy, you've added more locations that your data can be compromised: now it's at your house, on your thumbdrive, in your personal backups--and maybe, as I once had it, checked into a subversion repository and checked out on several different machines at home and work.
People always give me Gmail's adwords parsing of your email data as an example of why Gmail is creepy and untrustworthy but if you are really concerned about it, use PGP/GPG (Tutorial + Download or FirePG, firefox plugin). Now that's easier said than done. The average lay-user is not going to be comfortable encrypting their emails before sending them and decrypting them before reading them--but if you are really concerned about your privacy, it's a small price to pay--and the FirePG firefox plugin integrates beautifully with Gmail, allowing a seamless reading of encrypted email.
Once you have PGP/GPG setup, get my key and send me an encrypted message :)
This is a slightly different situation from Gmail because until I put some of my documents on Google Docs, the only place they existed was in my personal subversion repository and the thumbdrive that I checked them out on. Now, I'm faced with a little bit of a problem:
If I want to store information in Google Docs that I don't want someone to read, I have to encrypt it. This works well for standard Google Documents but it can't be used on Google Spreadsheets. This ends up being a security lag point and I'm constantly reminding myself not to make the spreadsheet transition yet. Even managing the Word-like Document system with encryption can be tricky, since you have to encrypt the data before you paste it into your Google Document, lest they auto-save an unencrypted copy and you miss all opportunity to keep that data private (once it's saved, it's in their backups and you can't ever be sure it's gone).
The thing to remember about online data storage is this: if you downloaded it from a server somewhere, it's already in the cloud--you might be lucky and be able to delete it but you can never be certain that it isn't sitting in someone's backup or cache of intercepted traffic. But if you have private documents, messages, etc that you want to store on the cloud or send to someone over the internet, the only way you can be sure your data is safe is if you encrypt it before it goes into any outbox, inbox, or text area of any kind in a web browser. In the end, security is only as good as the weakest link: if you are communicating/sharing data with someone else, make sure they are as concerned as you are--or they might just copy and paste your data into their unencrypted cloud backup system.