Michael Brown’s family gathered for Thanksgiving on Thursday. One seat at the table was left empty.

On that empty chair was a T-shirt emblazoned with a picture of the 18-year-old Ferguson teenager who was killed in August by police officer Darren Wilson. “Gone Too Soon,” the shirt said.

That holiday moment, captured in a photo shared by the advocacy organization Ferguson Action, was repeated over and over across the country Thursday and then tweeted under the hashtag #StolenLives.

“This year, Mike Brown’s parents will have an empty seat at the dinner table. So will thousands of other families who have lost a loved one to police violence,” said a statement from Ferguson Action, a coalition of St. Louis-area groups. “Stand in solidarity with them this holiday and save a spot for those who have been lost at your table.”

Similar photos were shared by the families of other high-profile African-American shooting victims, including Oscar Grant, killed in Oakland, Calif., by a transit officer, and Jordan Davis, killed in Florida by a civilian after an argument over loud music. They were tweeted under the hashtag #StolenLives.

Soon, families across the country posted photos on social media for Brown and others, calling it a new Thanksgiving tradition:

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#stolenlives #mikebrown #ferguson

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Just a day before Thanksgiving, police in Cleveland released surveillance footage showing a white officer shooting and killing 12-year-old Tamir Rice moments after jumping out of a police cruiser. On Thursday, empty seats and candy were left for Rice:

Stanford University students left an empty seat in their dining hall:

Activists are organizing another another holiday weekend tradition this week, calling for “Black Out Friday.” A group founded by the director of “Fruitvale Station,” a movie based on Grant’s shooting death, is asking people to boycott shopping on Friday.