noticed that all avatars are stored in the same directory, same for pictures. Probably it's okay if a site has 1000 members. But what if it has 10,000 members? 50,000? 100,000? and all pictures in the same directory? Is it a good idea? I've read somewhere that it's bad for security when there are too many files in the same directory. Not too mention it will be hard to delete such a huge directory, even from shell.
Not sure what to do about this problem, but it WILL become a problem for the growing sites.