DropBox reported that it had a hack of it’s files at 5:41 PM and had it patched by 5:46 PM, pretty good. It appears that DropBox has repaired the problem and contacted users.
In the case of DropBox, you should consider encrypting your files before posting.
This problem faced by DropBox would likely have been prevented with unit and/or regression testing. Of course, the concept of testing is something that all of the technologists strive to make it difficult for others to learn how to do. Also, the universities do a horrible job of teaching it, including my teaching processes. Dietel and Dietel mention it only in passing.
Also, if you are storing any information by others on a web site you should consider using services like LiveID, etc. and let the other company worry about the impact of hacks. This is a good and bad example of storing information on the cloud. If I store my information on a terabyte setting in my home office it is somewhat more secure against hacking. But that terabyte harddrive isn’t safer against being stolen, dropped, flooded, stolen/hacked/returned, etc.
Tough decisions to make. Oh hell, just write it down.
And by the way, Microsoft has a similar product with skydrive.