Twitter has pulled the plug on a popular US website which highlights and stores messages that politicians tweet then delete.
The tweets recovered by the Politwoops site were often deleted typos and accidental retweets, but it occasionally spotted more interesting changes.
Last summer it flagged up politicians who quietly deleted praise for Bowe Bergdahl, the soldier held hostage in Afghanistan who was rescued but later charged with desertion.
To collect the tweets, Politwoops had to use Twitter’s application program interface (API), which programmers use to run automated tools.
But Twitter says using its technology in this way violates its policies of giving its users privacy.
It said: “Preserving deleted Tweets violates our developer agreement.
"Honouring the expectation of user privacy for all accounts is a priority for us, whether the user is anonymous or a member of Congress.”
A European version of the site, which monitors politicians from the UK and beyond, appears to still be working.