Moms on Instagram are angry that the algorithm keeps deleting topless photos of their sons with long hair.

Some of them have started posting photos of their sons with the hashtag "longhairedboyrevolution"

Instagram head Adam Mosseri responded via Instagram story, saying that he restored the wrongfully removed accounts.

Visit Business Insider's homepage for more stories.

Moms on Instagram have started posting pictures of their sons in protest of Instagram's algorithm after the site kept flagging and deleting topless photos of boys with long hair. The algorithm apparently mistook them for girls, which would make the photos violations of Instagram's community standards.

Lauren Strapagiel at Buzzfeed News reported that @parkersavesthesea, Tori Spooner's account featuring her 4-year-old son, Parker, was deleted by Instagram two weeks ago, but Spooner had had issues with the algorithm for over a year before that. Photos of Parker were being flagged by Facebook, which owns Instagram.

Spooner told Buzzfeed that Facebook gave her a warning, stating that the photos violated the site's community guidelines. The account was then deleted because it had too many flagged photos, according to Buzzfeed.

Read more: These are the 20 most-liked Instagram posts of all time, from a picture of an egg to photos of Kylie Jenner and Selena Gomez

Other moms on Instagram said they faced similar problems, and many started posting photos of their long-haired sons holding signs reading variations of "Dear Instagram, I'm a boy. I just have long hair. Quit deleting my pictures," BuzzFeed reports.

One store that sells hand drawn clothing on Instagram, @finfirst, jumped on the trend and began selling shirts that say "Long live long haired boys." The account is named after the owners' own long-haired son.

Instagram's rules on this topic are a bit confusing. The site's community guidelines state that nudity is not allowed on the app. Its definition of child nudity includes visible female nipples on anyone above toddler age, but does not ban visible male nipples. The guidelines go on to explain that "for safety reasons, there are times when we may remove images that show nude or partially-nude children," like seemingly benign photos of kids taking a bath.

In a statement to Buzzfeed, the company admitted that it made a mistake deleting Spooner's photos, which did not violate any rules. The account has since been reinstated.

As Buzzfeed reported, Instagram and its parent company Facebook use machine learning and artificial intelligence to "proactively detect child nudity and previously unknown child exploitative content when it's uploaded." The signs the boys held tells Instagram that they are boys, assuming that Instagram's algorithm mistook them for girls because of their long hair.

Most of the #longhairedboysrevolution posts tagged Instagram head Adam Mosseri. On September 26, Mosseri posted an Instagram story using the hashtag, saying that he restored the wrongfully removed accounts, and included a link for others to appeal their deletions. He signed his note from "Dad of a long-haired boy.""