Let me just keep this one nice and simple

Having a web hosting account is handy at times.  It allows you to practically upload anything you want to share with friends, or to store online.  This is a blessing and also a curse when it comes to the web hosting business though.  While it is handy to be able to upload anything to a web hosting account, it is not always practical.  Sometimes, it might even be against the rules.
There are a lot of different file types out there, and here are three that you should make sure you do not ever upload to your own hosting account:

Personal Documents or Files

A lot of the time I see people trying to upload backups of personal documents and files to their web hosting accounts.  Not only may this be against your web host’s terms of service, it also might not be the best way to store your data.  The question you should ask yourself isn’t will be server have a security issue, it is when will my server have a security issue.  Out of date scripts, server flaws and everything else will give you trouble on the shared hosting account you are on – so uploading personal documents to store there is not too safe.  The better solution would be to go with a company that specializes in off site backups, such as Carbonite.

Website Backups

Another type of file I see people keep or upload to the server is a website backup.  Now, you might think you need to keep your website backup handy, so storing it on the hosting account might make a little ‘bit of sense.  Actually, just to be blunt – this is as intelligent as keeping all your money under your mattress, then complain that your broke after your house burns down.  The last place you want to store your website backups is the place you are hosting those files from.  I would recommend downloading a local copy to keep on your personal computer – then burn the files to a DVD or save them to another hard drive.

Illegal Files

Last but not least, we have illegal files.  Let me just keep this one nice and simple.  Don’t go uploading your favorite movie or music album to your hosting account.  Yes, it is illegal to share the files that way and yes, your web host will most definitely terminate your hosting account if they find out.
I hope this serves as a good reminder to all hosting customers out there today as to which files they should not upload to their web hosting accounts.  Now with some of these topics, there might be debatable points – however, I am just looking out for you and hopefully keeping you from getting your website taken offline or worse because of a lapse of judgment.