In recent years, women in Saudi Arabia have been using social media to speak up against certain customs and traditions that limit some of their personal freedoms. The most recent campaign to go viral on Saudi Twitter is one against the mandatory abaya dress code in the kingdom.

As per Saudi law - which is based on a fundamentalist interpretation of Sharia law - women, both foreign and local, must wear an abaya when out in public spaces, and locals must wear a hijab in some parts of the kingdom, including the capital city Riyadh.

In response to the law, a group of Saudi women have launched an online campaign under the Arabic hashtag "Abaya Inside Out" in protest of the kingdom's law.

The campaign asks women to stand in solidarity with the cause by posting photos of themselves in abayas flipped inside out as "a silent objection to being pressured to wear it," as one Twitter user put it. 

"Saudi feminists are endlessly creative"

"An act of civil protest"

"I will continue to wear abaya in this way to guarantee our freedom of clothing"

Countless women joined the online movement

"I'm in"

"I can't take anymore"

"I'm enjoying the astonished glares"

"Tonight I stand in solidarity with you"

"I hope to see everyone commit to this movement"

"I hope to see everyone commit to this movement: from school to university students to the disabled to employees and housewives. All you need to do is flip your abaya inside out. I'm going to do so starting tomorrow."

"I reject any form of limitation to one's personal freedoms"

"The simplest form of expressing rejection"

"Objection is a basic right"

"I am with you"

Not the first movement of its kind

Earlier this year, hundreds of Saudi women joined an online movement ... by removing their niqabs and hijabs.

It all started when Taraf Alasiri posted a photo of herself without a niqab and hijab, encouraging a full-fledged movement on Twitter.

"I cut my hair and removed the niqab ... and I wondered why I've been covering my face this whole time. I realized it's because of silly habits and traditions that don't allow me to be free," Alasiri wrote in a tweet. 

Women joined Alasiri by posting photos of themselves doing just the same, under the hashtag #SolidarityWithTaraf. 

In the past, women have been arrested for refusing to wear the abaya in public

In late 2016, a Saudi woman was arrested for tweeting a photo of herself going for breakfast in Riyadh without hijab or abaya. 

Last year, a social media star was also detained after a video of herself walking through a Saudi historic site wearing a mini-skirt went viral.

In February, a top Saudi cleric said women shouldn't be forced to wear abayas

In February, senior Saudi cleric Sheikh Abdullah Al-Mutlaq said women should not be required to wear abayas. The comments were made during his Friday television program.

Al-Mutlaq, a member of the Council of Senior Scholars, argued that the long loose-fitting robe is unnecessary to preserve modesty.

"More than 90 percent of pious Muslim women in the Muslim world do not wear abayas," he said, according to The National.

"So we should not force people to wear abayas."

In March, Crown Prince MBS said "Muslim women aren't required to wear the hijab and abaya"

Earlier this year, Saudi Arabia's Crown Prince Mohammed bin Salman was interviewed by journalist Norah O'Donnell.

During the interview with U.S. television channel CBS News, MBS said - among other things - that Sharia law does not require women to wear the hijab and abaya.

He explained that Sharia law only requires women to dress modestly, as it also does for men.

"The laws are very clear and stipulated in the laws of Sharia: that women wear decent, respectful clothing, like men," the prince said.

"This, however, does not particularly specify a black abaya or a black head cover. The decision is entirely left for women to decide what type of decent and respectful attire she chooses to wear," he added.