Twitter has a lot of explaining to do.

The The Playbirdssocial media platform is under scrutiny after several accounts noticed the search tool had begun to bar photos (as well as videos and news) tagged with the #bisexual hashtag -- and others.

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The hashtags #bisexual and #bisexuality are not the only ones to be filtered out by Twitter's search tools. Included in the block are words like "butt," "boobs," and various sexual slurs, but as historian and CUNY professor Angus Johnston (@studentactivism on Twitter) pointed out in a series of tweets, there are inconsistencies with what has been blocked and what hasn't.

You can read the entire thread here.

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Many people are calling out Twitter for the messy handling of blocking particular terms (like #bisexual) that aren't inherently sexual, yet grouping those terms along with other barred words that are—all while inflammatory phrases like #whitepride are not banned at all.

Searches for photos under the #lesbian and #gay hashtags still yield results. Mashablehas reached out to representatives at Twitter and will update this post when more information becomes available.

Meanwhile, the Twitter Support account has responded with a vague tweet. "We've identified an error with search results for certain terms. We apologize for this. We're working quickly to resolve and update soon," they said.

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The erasure of #bisexual and #bisexuality, in particular, on a popular platform like Twitter further buries the "B" portion of the LGBTQ community with even more social stigma than it's already faced. It's something people have been incredibly vocal about since the discovery that photos with #bisexual hashtag have been scrubbed from searches.

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UPDATEDNov. 5 at 5:06 p.m. ETwith an update from the Twitter Support account.