Here is Twitter’s full statement, compiled from a series of tweets.
Late last week, we discovered a technical issue that affected search results: searches for certain words related to sexuality did not populate complete results. We apologize for anyone negatively impacted by this bug. It is not consistent with our values as a company.
As outlined in our media policy, media that may be considered sensitive is collapsed in places such as search results, meaning that images and videos would be presented as a link, not automatically populated.One of the signals we use to identify sensitive media is a list of terms that frequently appear alongside adult content.
Many of these words on the list are not inherently explicit, which is why they must be used alongside other signals to determine if the content is sensitive.
Our implementation of this list in search allowed Tweets to be categorized based solely on text, w/out taking other signals into account. Also, the list was out of date, had not been maintained and incorrectly included terms that are primarily used in non-sensitive contexts.
When all Tweets containing certain terms were incorrectly collapsed on the photos, video and news search tabs, the search results in those tabs returned an error message indicating that no content was available.
We have audited the list and removed terms that should not have been included. We are making changes during the next 24 hours to correct this mistake. Once we are confident it is completely resolved, we’ll share an update here.