When a ATC unit fell within my area of responsibility, its ATC recorders were in a locked room. Following any incident which may call for later investigation, an authorised personl would enter the room, remove and impound the media, and install fresh media. The impounded media were then kept under tight security. After all, they may provide the only hard evidence in a criminal case.
Are security and confidentiality no longer important?
Either this was a recording made by someone illegally (and partially?) recording ATC traffic, or it really is a recording released by ATC. I wonder which?
In either case, a prosecution should follow.