From Activision to NuddistConnect.com to Zattoo, the AccountKiller database of more than 500 sites has links to each one’s deletion page. It offers instructions to remove your account or public profile on most popular social media sites. If you want to create an account it has a Blacklist of sites that don’t let you remove your profile.
You can also use this site to find sites to search for information on your subject. Start in the blacklisted sites as the subject will have a very hard time to delete his profile on these sites.
If you are trying to erase yourself or a client from the Internet, then you will need more that this site to accomplish your goal. Beware, it may be better to edit the profile and leave it in place — this is particularly important with some sites like Twitter.