A day after news hit that Twitter cut off the feed that fueled the deleted politician tweet site Politwoops, the site’s owner, the Sunlight Foundation, said it’s confused about the real reasons for the move.

“Sunlight is mystified as to why Twitter has changed its mind about Politwoops,” wrote Sunlight Foundation spokesperson Gabriela Schneider in an email to VentureBeat. Politwoops depended on an API from Twitter to supply the deleted tweets.

Sunlight Foundation president Christopher Gates wrote, in a eulogy to the fallen site at its blog, “Twitter’s decision to pull the plug on Politwoops is a reminder of how the Internet isn’t truly a public square.”

“Our shared conversations are increasingly taking place in privately owned and managed walled gardens, which means that the politics that occur in such conversations are subject to private rules,” Gates wrote, referring to Twitter’s terms of service for usage of its API.

Twitter shut off access to the API that let Politwoops track and publish the deleted tweets of politicians a few days ago. In essence, Politwoops was doing a public service by archiving politicians’ tweets, which Twitter doesn’t do.

Twitter had this to say in a statement yesterday:

We strongly support Sunlight’s mission of increasing transparency in politics and using civic tech and open data to hold government accountable to constituents, but preserving deleted Tweets violates our developer agreement. Honoring the expectation of user privacy for all accounts is a priority for us, whether the user is anonymous or a member of Congress.

The Sunlight Foundation has a long history of exposing the voting and campaign habits of politicians. The deleted tweets tracked by Politwoops were part of an effort to hold politicians accountable for their public statements.