Saving data online, such as in Google docs

A hot buzzword in software today is cloud computing. You may or may not have heard the term before, but I'm pretty sure you're already using cloud applications.

Do you use Yahoo's email, Google Docs for word processing and spreadsheets, Facebook, Twitter, etc...? They're nice because you don't need to install/maintain any software or worry about how much disk space you have. You can pretty much access these applications from any computer that has an internet connection. And because it's all online, you can easily share it with others.

Sounds pretty good, huh? I like using Google Docs for certain tasks, especially when I need to collaborate with others, but I'm a little more careful with anything I'd consider confidential in any way, at least more so for now. (Did you know Google mail/docs/calendar just came out of beta in July 2009?) When you use online applications, you are giving the service providers control over your data and you have to trust them.

Trusting the service provider
- You must trust that the service providers are storing your data securely, and that Mr. Stranger can't easily hack into their system and take your data.
- You must trust that the service providers have written their software correctly and that the code doesn't contain bugs that might accidentally leak your data to others.
- You must trust that the service providers won't look into your saved files, and give that data to others. (For example, to a competitor or a government.)

Trusting yourself/your friends
- You should use a good password - if someone guesses your password, they will have access to any of the information you have saved online.
- You must also trust whomever you have shared your documents with - that they have good computer habits and do not have an easily guessable password, and that they won't accidentally give access to someone else.

In addition to security, there is also the question of reliability. What if their service goes down? You won't have access until it's up. What if they go out of business? You better make sure you have a backup copy, if it's important. Also what if you delete something - can you be sure it has been completely deleted (including all backups)? You don't really know. (But hopefully it shouldn't matter because it wasn't something super confidential.)

 This seems to be the direction we are moving in, and we should at least understand what it means.