Wipe out superfluous accounts with Deseat.me
Deseat.me requires you to log in with either a Google or Outlook account, but if you're getting to wipe your internet presence out that shouldn't be too big of a concern.
Once you log in, Deseat.me will comb the account you logged in with for other accounts. All you have to do is choose whether you want to keep or delete that account and Deseat.me will do the work for you (some accounts have to be closed manually and Deseat.me will take you to the appropriate page in that case).
If you want to get rid of a bunch of accounts you forgot you had, Deseat.me is a good place to start.
Image: TechRepublic/Brandon Vigliarolo