Discussion of King Salman's decree permitting women to drive has flooded Saudi social media.
The policy, which will see women legally allowed to drive in Saudi Arabia for the first time, takes effect in June 2018.
The decision was greeted with joy by activists in the Gulf kingdom, many of whom have long campaigned for this change.
But in a deeply conservative state there was also anger and disapproval.
Early criticism focused on the "dangers" of women drivers. Hashtags such as "the people refuse women driving" were widely shared in the wake of the announcement. Many posts featured images of crashed cars captioned with disparaging remarks about women's driving abilities.
But supporters quickly co-opted the hashtags to poke fun at those who had initiated them.
Thousands of women celebrated the decision online, sharing pictures of the Saudi king and Crown Prince Mohammed bin Salman.
The crown prince, who is regarded as the power behind the throne, has promised Saudi women greater freedoms and a more active role in society as part of his Vision 2030 plans.
Social media has played a prominent role in campaigners' efforts to drive reform. Many of those activists welcomed the news online.
Loujain Al-Hathloul was detained for 73 days after being arrested attempting to drive across the border from the United Arab Emirates in 2014. She documented her experiences on Twitter.
Reacting to news of the decree, she tweeted, simply, "Thank God".
الحمدلله.— لجين هذلول الهذلول (@LoujainHathloul) September 26, 2017
Manal Al-Sharif, a women's rights advocate involved in the Women2Drive campaign, was arrested for driving in 2011. She welcomed the announcement but said that there was more still to be done.
"Today, the last country on earth to allow women to drive. We did it," she tweeted.
Ms Sharif, who now lives in Australia, pledged to switch her focus to the kingdom's guardianship laws. Women in Saudi Arabia must have a male guardian - usually their husband or father but sometimes brothers or even sons - from whom they require permission to travel, work or access certain healthcare.
Opposition scholar Madawi Al-Rasheed congratulated women's rights activists, but emphasised challenges which still lay ahead.
"Without an elected government and political representation, we will not benefit," she said.
The decision is the latest step in an apparent relaxation of Saudi Arabia's strict rules governing what women can do - a move that has not been met with universal approval.
On Saturday, women's participation in the country's National Day celebrations for the first time was heavily criticised by hardliners, while a cleric was suspended by the government for claiming that women could not drive because they have a quarter of a brain.
"What happened during the national day was enough," one social media user said.
"The committee [for promoting virtue and preventing vice] was absent and so the dregs of society came out of their dens."