Concerned that the Baltimore City Police Department routinely violates the First Amendment by threatening citizens who try to photograph or record police encounters, the ACLU of Maryland filed a lawsuit against BPD on behalf of Christopher Sharp, a man whose personal videos, including many of his young son, were deleted after he filmed BPD officers roughing up a female friend of his in the Clubhouse at the 2010 Preakness Stakes.
https://www.aclu-md.org/en/cases/sharp-v-bcpd