Instagram has a hashtag problem, but it has nothing to do with the flood of #swag, #follow4follow, #instagood or #YOLO spam that’s clogging your photo stream.

Instagram has censored more than 100 hashtags, apparently to keep you from searching for pornographic pics. The list of banned hashtags includes #sex, #bubblebutt and #ballsack. The problem: its censorship is incomplete and nonsensical.

On Sunday, my blog The Data Pack published a list of hashtags that Instagram blocks users from searching (it does not prevent users from posting hashtags, however). The list was an update on an earlier list published in August, pieced together by running a list of popular hashtags through Instagram’s developer API and watching out for a for the return of an error, “400 This tag cannot be viewed.”

The interesting part of Instagram’s censorship—and the recent update—is not that it chooses to limit what users can search, but the specific tags that it disallows. Users can search #gunsforsale, and, based on the most recent update tracked by Data Pack, are now free to track #faketits, #nakedtimes and #sexytimes. But, #petite, #poop and #bra are still searching dead-ends. Searching for #thinspo (a shorthand for thinspiration, which is often used to celebrate bulimia or anorexia) will result in a warning of graphic content and will inform users to find help with eating disorders, but the content will still appear.

While the intention of Instagram’s censorship was seemingly to filter out crude content, the original implementation fell short, blocking users from searching seemingly benign hashtags like #foodorgasm, #thesexpistols or #lazyasfuck due to a partial match of a blocked word. In fact, the block list appeared to include any tag that contained a profanity, a racial slur, or an explicit sexual reference, resulting in hashtags like #classybitch, #sofuckingtired and #jamesmotherfuckingfranco being blocked from searches. The update contains a much tighter set of blocked phrases and single words, but still raises more questions than it answers about Instagram’s censorship policy.

I've reached out to Instagram for comment on the extent of its censorship, but have not heard back. The company has said its list of censored terms is an “evolving and ongoing process.”

Hashtags are a digital language derived from internet chat rooms. They are integral to Instagram since they remain the only way to search photos on the image-based service. A user can post as many as 30 per photo. Including a popular hashtag, like #fashion, enables an image to be seen by any of the services 150 million active users via the app’s “Explore” tab who may not directly follow a user. In other words, hashtags are a way to promote a photo.

Many of the single word tags like #fuck, #bitches, #porn remain on the blocked list, but many longer variations, like #fuckfriday and #mybitches are now searchable. #Dildo and #chink were once banned but can now be searched, though #wet, #shower, and #popular remain blocked. Users can search #faketits, #underboob and #boobz, but not #sideboob, #boob or #boobies.

In many cases, adding an additional word to one of the blocked tags will result in a page full of results. Users are still blocked from searching for #lingerie, but are free to search #newlingerie or #sexylingerie, which returns over 2,000 images that wouldn’t be out of place in a Victoria’s Secret catalogue.

Combining two banned hashtags together also appears to evade censorship. Both #sexy and #nude are blocked when searched by themselves, but #sexynude returns a full page of results, none of which are particularly sexy, or completely nude. Similarly, both #hardcore and #porn are blocked when searched individually, but #hardcoreporn returns nearly 600 photos that would hardly be described as pornographic.

In fact, finding anything remotely pornographic on Instagram seems to be quite difficult, even when you go looking for it—and even when you evade its censor.

A banned hashtag search tool created by Data Pack lets users take a peek behind Instagram’s censorship curtain by searching for photos that have been publicly cross-posted from Instagram to Twitter, which doesn’t censor any search results. Searching for even the more explicit hashtags on the banned list, most results would be lucky to attract higher than a PG-13 rating.

The results for #nipple reveal less than a handful of male-only nipples, and the hashtag #naked returns more juice than bodies.

It seems that Instagram users are far more interested in posting photos of what they are drinking than naked selfies. But if they are, you won’t find them by searching for #nakedselfies.