The court heard the pair were in a WhatsApp group which discussed having a 'spit roast' and said sex with the woman was 'like a merry-go-round'.
But just hours after they were cleared, in response to the wider issues raised by the case and in support of the woman and others in a similar position, thousands of people tweeted #IBelieveHer.
To everyone giving out about the protests today, unfollow me because I've already unfollowed you. This moment is so much bigger than the case. pic.twitter.com/8GkFKYB8BM
The hashtag was trending in the UK, Ireland and worldwide and on Thursday a rally outside the Laganside courthouse took place along with others in Derry, Cork, Limerick, Galway and Dublin.
Both Jackson, 26, and Olding, 25, were cleared alongside their friend Rory Harrison, 25 - who denied perverting the course of justice and withholding information.
Another friend Blane McIlroy, 26, was accused of one count of exposure but the four defendants were cleared of all charges relating to the alleged incident in June 2016.
The Belfast rally was organised by Reclaim the Night Belfast, which is a group which is campaigning against harassment and gender-based violence.
On Facebook, the group wrote: "The feminist movement is calling a rally in response to the impact of the recent rape trial in Belfast.
"There is a lot of anger and upset among women who have observed the treatment of the [woman] in this case and found it harrowing and re-traumatising."
The hashtag #IBelieveHer was trending in the UK, Ireland and worldwide on Twitter just hours after the verdicts were returned.
Many used their messages to support the woman who gave evidence throughout the trial, which was described by the judge as "probably the most difficult trial any jury in Northern Ireland has been asked to adjudicate on".
After the case yesterday, Jackson - who was also cleared of a separate charge of sexual assault - said: "I'd just like to thank the judge and the jury for giving me a fair trial, my parents for being here every day, as well as my brother and sisters.
"Out of respect for my employers I've nothing further to comment."
Meanwhile, Olding's solicitor Paul Dougan, read out a statement on behalf of the rugby player.
He said: "I want to acknowledge publicly that though I committed no criminal offence on the evening of June 28, 2016, I regret deeply the events of that evening.
It is alleged that Jackson replied on the same WhatsApp messaging service: 'There was a lot of spit.'
I’m exhausted. I’m going to sleep. Whether they’re rapists in the eyes of the law or not, they’re inhuman dirtbags. I’ll leave you with their choice words about a women they knew to have left their company bleeding and crying. #IBelieveHerpic.twitter.com/7PzQ2bkn30