Hashtag activism gets personal.

When Ajay Rochester posted a photo of model Laura Wells on Feb. 14, she was just having, as she calls it, a “normal Instagram rant”: “How the f— can this woman be considered plus size? … Where is there PLUS of anything. Anything less of her and she’d be a MINUS something. #dropthePLUS”

It’s the sort of discussion that the Australian actress and author has been having for years, but “I didn’t think the whole world would see it,” Rochester says. Three days later, model Stefania Ferrario posted a photo with “I am a model” written on her mostly nude body: “I am a model FULL STOP. Unfortunately in the modelling industry if you’re above a US size 4 you are considered plus size, and so I’m often labelled a ‘plus size’ model. I do NOT find this empowering. #droptheplus”

A hashtag campaign was born. Call it the digital bumper sticker, where the audience is the world and the intersection is Twitter, Instagram, Tumblr, Facebook or Pinterest. The hashtag — indicated by a keyboard’s “pound” symbol — was quickly adopted as an activism tool because it allows social media users to find posts that use that same hashtag — and hopefully, ignite a conversation.

You may recall #OccupyWallStreet (to protest economic inequality), #Kony2012 (to arrest war criminal Joseph Kony), #IceBucketChallenge (to encourage donations to ALS research) and #JeSuisCharlie (after the terrorist attack on French magazine Charlie Hebdo). Now these online catchphrases are being used to promote female-positive statements. Last week, “Good Morning America” launched a #GMABodyProud campaign to fight body shaming in advertising.

“If you yell in a loud room, no one can hear you, and no one cares,” Rochester says. “But the hashtag enables you to bring the voices together to scream at once and scream the same thing. It wasn’t really me who made #droptheplus go off — it was the voices of the women who agreed.”

In addition to activists like Rochester, brands and organizations have launched popular rallying cries, often piggyback- ing on current events to gain visibility.

In 2011, the Representation Project, created by Bay Area filmmaker and former actress Jennifer Siebel Newsom, used the Super Bowl to promote hashtags #NotBuyingIt and #MediaWeLike to inspire people to point out sexist advertisements. In 2014, it launched #AskHerMore, which many saw during this year’s Academy Awards arrivals.

“Red-carpet events can be incredibly uncomfortable and unnerving (not to mention superficial),” Newsom said via e-mail. “We created the #AskHerMore movement to encourage and celebrate reporters who ask the women of Hollywood about more than just their appearance.” According to Newsom, the campaign has reached 25 million people and drew support from Lena Dunham, Reese Witherspoon and other high-profile celebrities.

Dove launched its #SpeakBeautiful campaign on Oscar night to encourage women and girls to shift negative conversations into positive ones, and soon after, it launched #ChooseBeautiful to encourage women to think positively about themselves.

According to a 2015 social media study commissioned by Dove, 82 percent of women feel that the beauty standards set by social media are unrealistic. The study also found that almost three-fourths of the 1,072 women studied believe that social media comments critiquing women’s beauty are destructive to their self-esteem.

“Dove has been having a conversation with women about beauty, self-confidence and body image for a long time,” says Dove Brand Director Jennifer Bremner. “And that conversation is now happening in social media as much as anywhere.”

These recent campaigns seek to counter confidence-sapping content, such as the pseudonatural #wokeuplikethis posts; those who compete for “likes” with selfies; and negative comments about oneself or others.

“Today’s youth are socialized into society through networked culture,” says Microsoft researcher and social media expert Danah Boyd, who partnered with Dove on the #SpeakBeautiful research, in an e-mail. “As a result, social media makes visible the unhealthy beauty and self-confidence messages that surround women (especially young women).”

Research shows that people’s perceptions of beauty are shaped by those around them — which makes social media an ideal vehicle for influencing the popular opinion, Boyd continues.

San Francisco designer and technologist Chris Messina invented the hashtag in 2007. He liked that using “#” before words was cheap, effective and didn’t require permission. “Like the Internet, (social media) should be a vehicle for all sorts of discourse — it makes conversations more vibrant,” Messina says.

While it’s relatively easy to gauge the number of times that a hashtag has been used, measuring the impact of that hashtag campaign — or conversation — can be tricky. But experts argue that hashtag activism isn’t just “slacktivism,” as it has often been dubbed.

The point, says Stanford graduate student Jessica Tonn, who recently completed a master’s thesis studying hashtags, is to increase awareness and show solidarity and support for a cause. “It’s about awareness and interactivity between users on multiple platforms.”

Take, for example, a 2014 Victoria’s Secret ad campaign that featured underwear-clad models and the words “The Perfect ‘Body.’ ” After the resulting outcry included the rebuttal #IAmPerfect, the brand ultimately changed its wording to “A Body for Every Body.” Earlier this month, Victoria’s Secret faced more pressure when Lane Bryant introduced #ImNoAngel, a campaign that clearly references the Victoria’s Secret angels.

In comparing the 2015 Oscars ceremony with 2014’s, Dove and Twitter found that negative beauty conversations about others two weeks after the event were 43 percent lower than last year.

Boyd says that so-called hashtag activism is especially useful for causes, like #SpeakBeautiful, that ask people to think about the norms and values within their culture, rather than causes in which awareness alone does little to make a difference (such as systemic poverty issues).

“There are people in Saudi Arabia, Italians — French people are discussing #droptheplus,” Rochester says. “And the fact that I can have a conversation with them is mind-blowing and exciting.”

“The hashtag enables you to bring the voices together to scream at once and scream the same thing. It wasn’t really me who made #droptheplus go off — it was the voices of the women who agreed.” Ajay Rochester