Twitter is somewhat notorious for using a technique known as “shadowbanning” to punish users that violate their rules; if a user tweets too quickly, makes too many tweets using a certain hashtag, retweets too much, or says something controversial, they get shadowbanned. When a user is shadowbanned, other users on Twitter don’t get any notifications about the shadowbanned user’s interactions with their tweets, and the shadowbanned user’s replies don’t show up. All tweets from shadowbanned users don’t show up in the Twitter search, either. Most of the time, when a user is shadowbanned, they aren’t aware of it unless they use another account and/or are logged out, as replies and tweets from a shadowbanned user are still visible to themselves.

Shadowbanning usually happens sporadically and not very often, and the typical shadowban lasts for a day to two days at worst. However, in April 2018, numerous users on Twitter had been getting shadowbanned for much longer than that, even up to weeks – all just for showing their appreciation.

In early April 2018, Twitter was cracking down on their spam filtering – and a glitch in their system left the phrases “thank you” and “thanks” on their blacklist of phrases that users could get banned for saying. Users who said these innocuous phrases would get shadowbanned for extended periods of time, with some users even reporting getting locked out of their accounts as opposed to the less severe shadowban. Rumors also spread that users who said “I love you” got shadowbanned as well, though no evidence to confirm this has been found.

Twitter cleared up the situation April 25, in which they reported to The Daily Dot that the shadowbanning was due to a glitch which had been rectified that same day.