A US police officer played a Taylor Swift song on his phone in a bid to prevent activists who were filming him uploading the video to YouTube.The video platform regularly removes videos that break music copyright rules.
However, the officer's efforts were in vain as the clip of the encounter in Oakland, California promptly went viral.
Alameda County police told the BBC it was not "approved behaviour".
The video was filmed by members of the Anti Police-Terror Project (APTP), which says it is a coalition that seeks to "eradicate police terror in communities of colour".
Some of them were protesting outside the courthouse at the pre-trial hearing of a San Leandro officer charged with the manslaughter of a black man.