Protesters are responding. On Sunday, as another demonstration turned into a violent confrontation with the police, some of those involved shined laser pointers at police cameras and used spray paint to block the lenses of surveillance cameras in front of the Chinese government’s liaison office. Riot officers carried cameras on poles just behind the front lines as they fired tear gas and rubber bullets.

The protesters ’ ire intensified after the police removed identification numbers from their uniforms, presumably to keep violent misconduct from being reported to city leaders . To some protesters, the move suggested the police were taking a cue from the mainland, where officers lack public accountability and often do not identify themselves.

“Why do the police get away while we’re getting attacked?” said Billy Tsui, a hairdresser. “If they do something wrong, they should face legal consequences.” He said that he favored peace over violence but that he also had some sympathy for the Telegram group exposing officers as a check on police misconduct.

“The original intention is just to identify who are the policemen,” Mr. Tsui, 21, said. “If they hide their numbers and don’t show their identity, this is the only way to know.”

Hong Kong police representatives have said personal information about officers and their friends and relatives had been posted online in an act known as doxxing. On July 3, the police said they had arrested eight people accused of, among other things, disclosing personal information without approval. A police spokesman said members of the police force had reported more than 800 incidents in which officers or their family members had been harassed following the data releases .

“ Dadfindboy ” — a play on the name of a Facebook group created under the auspices of helping mothers find their children, but which ultimately became a way for pro-government groups to gather photos of protesters — is one forum for the doxxing of police officers. By turns facetious, juvenile, cruel and profane in tone, the channel repeatedly reveals personal information and photos, some of them intimate, of the family members of police officers, sometimes with intimate social-media photos.

The channel has featured calls for violence, often in cartoonish ways, although there is no proof that it has incited any specific acts. One post instructed protesters on how to master using a slingshot. Another explained how to make a blow torch using aerosol deodorant. A recent poll queried the channel’s followers about how best to deal with the police. Options included prison, gas chamber, live burial, guillotine, and machine-gun execution. Live burial prevailed with about one-third of the vote.