According to messages sent to suspended users, the use of the Tennessee city name violated prohibitions on posting personal information.
The inadvertent damage quickly spread across Twitter as users trolled each other, trying to get unsuspecting accounts to tweet the suddenly-forbidden word. The apparent flaw in the auto-moderation system went unaddressed for several hours as more and more users found themselves temporarily prevented from using the service. Although some users noticed certain accounts (mainly verified ones) weren't being hit with bans, it affected enough users that the ripple effect was not only noticeable, but covered by many mainstream media outlets.
The bans were lifted several hours later with no explanation from Twitter other than that an unspecified "bug" had resulted in tweets containing the word "Memphis" being removed and features limited for those accounts.
That explanation was not entirely clear. Given the "Memphis" bug's link to alleged violations of Twitter's policies against posting other people's personal information, it was speculated the ban on a single city name may have been the result of an erroneously-completed form on the moderation side. Systems security professional SwiftOnSecurity took a plausible stab at the possible root cause of this improbable series of moderation events.
What's possible is a Twitter staffer tried to block a street address, but the postal syntax acted as an escape sequence, or the original was multi-line and they only pasted the city.
If so, every use of the word "Memphis" was considered to be a post containing a full address Twitter had targeted for removal under its personal information policy.
Decisions to be made by Twitter:
- Should moderation of the posting of personal information be handled with automation, given the potential for errors to scale and compound?
- Should a better stop-gap process be put in place to head off future events like these?
- Should users be given better explanations when moderation-at-scale results in features being limited for users affected by moderation bugs?
Questions and policy implications to consider:
- Should a stop-gap measure be put in place to prevent errors like this from becoming multi-hour failures?
- Have Twitter's moderation efforts resulted in a noticeable limitation of the spread of personal info?
- Is all publication of personal information considered a violation of policy? Or are exceptions in place for information considered to be of public interest?
Resolution: Twitter restored accounts and tweets targeted by its "Memphis" bug within hours of its emergence. However, the company's moderation team has yet to explain exactly went wrong or what Twitter has done to prevent its recurrence.
Written by The Copia Institute, April 2021