At this point you may well have become a member on dozens (maybe hundreds) of websites. You probably use a majority of those sites rarely (if at all). It’s time to quit those accounts (and by doing so delete any personal profile you may have provided in order to join that site). You can quit many accounts more easily by using AccountKiller. This site takes you step-by-step through the process of closing your account on numerous sites:
NOTE: You may wish to check their blacklist first: sites that make it difficult (in some cases, impossible) to delete your personal profile. On the list and of special interest to genealogists: MyHeritage.com. If you’re a blogger, you’ll be interested to know that WordPress.com is on the blacklist.