Follow this dead-simple guide to force any Twitter user—from Oprah to Kutcher—to follow you. No, seriously. (Update: Here's what happened.)
I have no idea how a hole this large could be left in a service as popular as Twitter, nor do I understand why it hasn't been shut yet. What I do understand, though, is that Oprah is following me right now, and receiving my DMs. So anyway, here's how it works:
1. Open the Twitter web interface (I haven't been able to get it to work in the apps I've tried)
2. Tweet "accept username", as in "accept oprah"
3. Wait a few seconds. You may get a server error, but that means it's worked.
4. Check your followers list
This command is either a remnant of a system that isn't in use anymore, or exposes something fundamental about the way Twitter works. (Typing "follow username" lets you follow someone, too.) Either way, ha, holy shit. Let us know how it works—and when it stops—in the comments.
UPDATE: Twitter is apparently already on the case: Most accounts are currently showing 0 followers and 0 followed, so there's no way to tell if the trick still works. More as we get it.
UPDATE II: Says Twitter:
UPDATE III: Looks like it's over, but there's still quite a mess to clean up.
UPDATE III: Following/Follower counts are back, but anyone you force-followed is still listed.
—Thanks, Bora Kırca and Güntekin!