Basically, if it is legitimate information, it most likely will never be removed completely. Because when you go to a website, photos and other information will be stored on your computer in your "cache". As many people could see the information, it will be stored in more peoples caches. The information can be removed, but it will likely still in other peoples places too. For example, when a search engine such as google comes across your site, it will be stored on Googles' servers for people to find on Google. Other search engines will do this too. And depending on how often the search engine updates their servers, it may take even longer before your information is removed.
Lets take an example. Say you put a photo on Facebook, but a few days later, want to take it down. You can, but it will still be stored in facebooks servers for at least 90 days. At this point, Facebook will create another backup of their servers, erasing your photo.
But, if you want it taken down quicker, you may take legal action, if;
* You didn't put the photo up, someone else did without your permission,
* It is a photo of illegal activity, or is breaching some kind of copyright (facebook may take legal action against you for violating the TOS
Note:
Copyright laws apply to all information on the internet.
Generally, their may always be a copy of your photo/information somewhere on the internet, so think carefully before you put the information/photo onto the web.