Twitter has banned a watchdog that kept track of celebrities' deleted tweets

A website that monitored public figures' Twitter profiles for deleted tweets has been shut down by the social network.

Post Ghost, which only launched on July 6, acted as a kind of watchdog, tracking when certain users deleted their old posts and them publicising them.

It's similar to Politwoops - an explicitly political service that monitors the Twitter feeds of politicians around the world, flagging up tweet deletions.

But while Twitter is happy to let Politwoops run, the same is not true of Post Ghost.

In a blog post, the service has shared an email it says it received from Twitter on the day it launched on ProductHunt, accusing it of violating the social network's Developer Agreement, which prohibits the monitoring and displaying of deleted tweets, and demanding that the service is shut down.

Post Ghost has complied, and is no longer available. But it has also shared an open letter on its website attacking Twitter's decision, framing itself as a companion to Politwoops and arguing that " Political speech ... is not an activity limited to politicians."

Here's Post Ghost's defence of how it chooses the users it chose to highlight the deleted tweets from, and why it does it (emphasis ours):

Of course, not every Twitter user should have their deleted tweets recorded - most people use Twitter as a personal account, and we firmly agree with Twitter's commitment to their privacy. However, Twitter maintains a list of public figures called verified users - about 0.05% of their user base - for whom Twitter acts as an outsized, instantaneous megaphone to reach vast numbers of followers. PostGhost only reports on half of this small subset - verified users with tens of thousands of followers, or more. We believe that for such prominent verified Twitter users, the public has a right to see their public Twitter history, whether or not they grow to regret the statements they've made.

...

When a public figure makes a public statement in the real world, be it in print, in person, or on their own website, writers, bloggers and individuals have the right to reprint and discuss that statement at will, even if the speaker wishes he or she could take it back. As Twitter becomes the default worldwide platform for online speech, losing that right is a loss for public discourse as a whole.

In short: Prominent public figures' comments and statements have always been subjected to retroactive scrutiny. Twitter, by removing that possibility, is weakening public debate.

As a private company, Twitter doesn't have any legal obligations to uphold free speech or maintain certain standards of "public discourse" - much like a shopping mall can eject protesters, even if the protesters aren't breaking any laws.

But Post Ghost argues that the social network should nonetheless try to uphold more nebulous concepts of accountability, given its prominence in the contemporary political debate. It points to a previous statement by CEO Jack Dorsey, who said that "we have a responsibility to continue to empower organizations that bring more transparency to public dialogue."

That said, Arjan el Fassed, director of Open State Foundation, which manages some Politwoops accounts, cautioned against drawing direct parallels between Post Ghost and Politwoops.

"There is a big difference" between the two services, he told Business Insider. "Politwoops only publishes deleted tweets by politicians and public officials. These are people who hold legislative, administrative, or judicial positions, whether appointed or elected. PostGhost just took the list of verified accounts but these accounts are not limited to just public officials or even public figures."

Twitter did not immediately respond to a request for comment.

Post Ghost will no doubt be hoping that this furore plays out similarly to what previously happened to Politwoops. The politician-tracking service had existed for some time before being banned abruptly in August 2015 for violating Twitter's terms of service. Dorsey then reversed this decision in December 2015, with the service starting to come back online in January 2016.

However, Politwoops still exists in a weird legal limbo. It unambiguously violates Twitter's terms of service - just like Post Ghost does. It only exists because of the good grace of Twitter's leadership.

This uncertain status means other services may continue to get threatening legal letters, even if they fulfill similar - and equally valuable - purposes.