A campaign by the New York Police Department (NYPD) to improve communication with the public backfired after its Twitter page received thousands of negative tweets.
A campaign to promote the force's image via social media produced a flood of pictures of alleged police brutality and tweets critical of the force being shared at a rate of thousands an hour.
The department yesterday invited Twitter users to submit pictures of themselves with NYPD officers using the hashtag #mynypd, promising some would be posted to the NYPD Facebook page.
Within hours, a torrent of images depicting apparent police brutality, violence and controversial tactics, most of which occurred under former New York Police Commissioner Ray Kelly, deluged Twitter.
By this morning, the #mynypd hashtag had been tweeted more than 94,000 times.
At 7am (midday Irish time) #mynypd was still trending at a rate of 3,400 an hour, according to hashtags.org, a Twitter analytics website.
The tweets included images of violence from New York's Occupy Wall Street demonstrations, pictures of an NYPD officer pointing a gun at a dog, and an officer asleep in a subway car.
Images and tweets also referred to the fatal, controversial New York police shootings of Sean Bell in 1999 and Amadou Diallo in 1999, each of which led to criminal trials in which all the officers were acquitted.
After the campaign appeared to backfire, the department issued a two-sentence statement saying that it was "creating new ways to communicate effectively with the community".
"Twitter provides an open forum for an uncensored exchange and this is an open dialogue good for our city", the department said.
Police Commissioner Bill Bratton said today that he would expand the campaign.
The viral campaign has spread across the US, sparking similarly critical images and tweets around hashtags aimed at police departments in Miami, Detroit, Los Angeles, Oakland and Chicago.
Commissioner Bratton noted that earlier this month, someone had captured a picture of a New York transit police officer guiding a blind woman to the subway, and posted it online.
He said: "Within about three hours, almost half a million people had basically seen that photo. What is wrong with that? We're going to continue that. Send us your photos, good or bad.
"The reality of policing is that often times our actions are lawful, but they look awful.
"Most of those photos that I looked at are old news."
The commissioner was appointed by Mayor Bill de Blasio to take over from Mr Kelly, who served for 12 years under Mr de Blasio's predecessor, Michael Bloomberg.