This week's 60th anniversary of the Montgomery, Ala., bus boycott for a moment focused attention on Rosa Parks, the black woman who lit the torch that ignited the civil rights movement led by the Rev. Martin Luther King Jr. by refusing to give up her seat to a white man. It's interesting that six decades later, another woman is being credited with starting the Black Lives Matter movement, which is an extension of what Parks began in 1955.

San Francisco activist Alicia Garza rather serendipitously used the phrase in a Facebook post decrying the 2013 acquittal of George Zimmerman, the Florida neighborhood watch leader who shot and killed unarmed black teenager Trayvon Martin. Garza's post urged African Americans to work together to ensure that "black lives matter."

Community organizer Patrisse Cullors saw the post and created the hashtag #BlackLivesMatter to solicit social media comments from others with similar views. The response was overwhelming. The hashtag became a slogan that appeared on posters and T-shirts across the country. An episode of Law and Order SVU depicted a police-shooting protest with a huge Black Lives Matter banner in the background.

Seizing the momentum, Garza, Cullors, and Opal Tometi created a Black Lives Matters website and used Facebook, Twitter, and Tumblr to connect with people who voiced similar concerns about the treatment of African Americans and other minorities. Paying tribute to the 1960s, they helped organize a 21st-century Freedom Ride that traveled to Ferguson, Mo., to protest the 2014 death of another unarmed black teenager, Michael Brown, who was shot by white police officer Darren Wilson.

Black Lives Matters now claims to be an organization with 26 chapters, but the term is used loosely. Rather than having a leader, Garza told one interviewer that the group is "leader-full," meaning many people play leadership roles.

That same scattershot approach applies to Black Lives Matter's stated goals, which range from ending "police terrorism," as Garza puts it, to improving the pay of domestic workers, to bringing attention to the murders of transgender women. In a USA Today interview, Cornell University professor Travis Gosa described Black Lives Matter as "unapologetically queer, black, multiracial, feminist, digital, atheist or at least nondenominational, and young."

Because its goals aren't always as specific as being allowed to drink from a water fountain, attend any school, or vote, Black Lives Matters has opened the door for others to define what it is. Gov. Christie, for example, insisted on the presidential campaign trail that Black Lives Matter wants to kill police officers because of a chant he heard at a protest rally. But there's nothing about killing police on the Black Lives Matter website.

Garza has called for more oversight of police departments, including civilian review boards, but she also said she doubts that any institution "rooted in the legacy of catching slaves" will ever act as if black lives matter.

I wouldn't call Garza a modern Rosa Parks. The courage it took for a black seamstress in 1950s Alabama to defy the white establishment and risk not just jail but her very life to help bring an end to segregation cannot be duplicated by posting an insightful comment on Facebook. Parks couldn't get work after her protest. She and her husband eventually moved to Detroit, which she said wasn't that different from Montgomery when it came to the unequal treatment of black people. But she felt safer there.

Garza, Cullors, and Tometi deserve credit for building on the legacy of Parks and using social media to continue a movement that didn't start with them and, unfortunately, will likely need to continue long after they have hung up their activist hats. In an interview for the Marguerite Casey Foundation website, Garza said, "We did not start Black Lives Matter as a hashtag. Hashtags are not movements." But she has used that social-media device to energize people to action, just as Rosa Parks did when she took a seat and refused to get up.

Harold Jackson is editorial page editor for The Inquirer. hjackson@phillynews.com