The process of direct linking to websites files such as images, videos etc is called as Hot Linking. It is like using an image (tag/image link) which you have found on someone else web page, and would be using on your blog. Every time the blog is browsed image will be shown because it is Hot linked from it’s original source.

This becomes a point of concern when your website is Hot linked by someone else.

Let me explain
Every website has a fixed bandwidth (bandwidth - Amount of data transferred from website to a users computer). When any internet user browses a website and if that website is hot linked to your site then your website’s
bandwidth is used in transferring the requested data.
??? => This means you are paying for the bandwidth which is not used by you.

To overcome Hot linking(Bandwidth Theft) Hotlink Protection is used. It prevents other websites from directly linking to files (as specified above) to your website.
Hotlink Protection can be set from Plesk Control Panel as well.