Joining others in their protest against the nudity censorship policies incorporated by Facebook in its family of apps, several porn artists protested outside Instagram’s Silicon Valley headquarters.

The adult film artists have described Instagram’s nudity rules vague, inconsistent and threatening to their livelihood, The London Free Press reported on Wednesday.

“Today (Wednesday) was such an amazing day and I am so thankful to my team, our supporters, but most importantly, our members and performers who joined this fight. We have proven we can be heard! Go UNION!!!@APAGunion,” Alana Evans, president of the Adult Performers Actors Guild (APAG), tweeted.

According to its Twitter bio, the APAG is a federally recognised union in the US organising actors and actresses in the adult film industry.

Adult film star Amber Lynn alleged that her Instagram account was disabled for “false allegation”.

According to media reports, Lynn had been building her brand on the Facebook-owned photo-messaging platform for the past five years and had gathered over 100,000 followers.

Lynn accused the platform of neither answering any queries nor giving an opportunity to correct any problems or avoid them in the future.

Commenting on Lynn’s concerns, APAG tweeted, “Why would they reactivate the account, only to take it down again within 24 hours without explanation? Amber Lynn wants them to make it where they let the user know what exactly they did wrong instead of the generic ‘doesn’t meet guidelines’.”

“Instagram’s policies are totally opaque, I have no idea how they enforce them,” the report quoted porn artist Betty Tompkins, who was also de-platformed from Instagram as saying.

According to Instagram’s community guidelines, naked images are banned on the site.

“We know that there are times when people might want to share nude images that are artistic or creative in nature, but for a variety of reasons, we don’t allow nudity on Instagram. This includes photos, videos, and some digitally-created content that show sexual intercourse, genitals, and close-ups of fully-nude buttocks. It also includes some photos of female nipples, but photos of post-mastectomy scarring and women actively breastfeeding are allowed,” the policy states.

Earlier in June, about a 100 people stripped naked in front of Facebook’s New York headquarters as part of a protest against what they view as censorship regarding Facebook and Instagram’s policies around artistic nudity.

However, later in June, the social networking giant confirmed that it would meet the National Coalition Against Censorship (NCAC) and re-think its stance on artistic nudity.

The NCAC launched the #WeTheNipple campaign in April to call for a change in the policies of Facebook and Instagram to allow photographic artistic nudity.