Hack the Planet.But it's a lot harder to get an anonymous phone number. You need to buy a burner phone and SIM for cash, wait two weeks for the CCTV system in the store to overwrite the video of the transaction, then activate your phone far from home. Once you've used it to get a Twitter account-creation authentication SMS (again, nowhere near your home or office, and nowhere where there's a record of you having traveled to), you need to destroy both the phone and the SIM. That's just to set up the account!
Previously, previously, previously.