SOCIAL MEDIA UPHEAVAL: What It’s Like to Get Doxed for Taking a Bike Ride.

Weinberg didn’t know what “doxing” meant, but it was happening to him: Someone posted his address. Detective Lopez didn’t answer his call, but soon someone with the police department contacted Weinberg to let him know that officers would be patrolling the area around his home because he might be in danger.

Detective Lopez reached him around 11 p.m. and they agreed to meet the next morning. At 11:47, Weinberg tweeted, “I recently learned I have been misidentified in connection with a deeply disturbing attack. Please know this was not me. I have been in touch with the authorities and will continue to help any way possible.”

His fiancée in New York, he spent the night alone, refreshing Twitter, watching helplessly as people tried to destroy his life. And Weinberg wasn’t even the only one: Another man, a former Maryland cop, was wrongly accused, too. The tweet accusing him was retweeted and liked more than half a million times.

At 7 a.m., Weinberg brought his bicycle and his helmet with him to the police station. Detective Lopez told him he was free to go and the department would issue a report excluding him as a suspect.

On Twitter, Maryland attorney general Brian Frosh sent Weinberg a message. “I am sorry for what you are going through. Police have a suspect. Can I post something that would help?” Hours before Weinberg was falsely accused, Frosh had asked all of Twitter for help finding the man in the video. “If anyone can identify this man, please let me know,” he said, and nearly 50,000 people retweeted him.

“I could use any help you can give. Can we speak quickly?” Weinberg said.

On the phone, Frosh — who did not return a request for comment from Intelligencer — was empathetic. He acknowledged that he had, in some way, contributed to Weinberg’s circumstances. He sent a tweet confirming that there was a suspect and “it is not Mr. Weinberg.” (228 retweets.)

On Friday, police arrested Anthony Brennan III, a 60-year-old from Kensington, Maryland, and charged him with three counts of second-degree assault.

Weinberg told a reporter he was “dizzy” after what he went through. . . .

As for the woman who shared his home address: She deleted it and posted an apology, writing that in all of her eagerness to see justice served, she was swept up in the mob that so gleefully shared misinformation, depriving someone of their own right to justice. Her correction was shared by fewer than a dozen people.

It’s like Twitter serves as an amplification system for toxic ideas.