Why Do They Want To Encrypt?
US Government law enforcement agencies encrypted to prevent bad guys from listening. Most people who purchased scanners were not listening to the Feds, and the media didn't listen to them on a regular basis either.
However, Local, County, and State government agencies are monitored on a routine basis by scanner enthusiasts, members of the general public, the media, and bad guys. I personally believe the primary reason why these agencies encrypt is to prevent the media and members of the general public from showing up at incidents.
The Internet has completely changed the way in which news is gathered and reported. News articles, still photos, and videos are disseminated immediately via the Internet (cellphones with cameras and smartphones are everywhere). Previously, news had to wait for the next scheduled radio or tv broadcast, or the next publication date in the case of hard copy periodicals. In the past, video was captured only with sophisticated camera equipment and still photos required film to be developed. Now everything happens instantly.
Politicians don't like to read bad news about their respective communities. Prosecutors don't want photos of crime scenes appearing other than those taken by their staff members. It's very tough to control the flow of information now that everything happens in a flash. But one way to stop "bad news" and potentially harmful photos is to prevent anyone from knowing about news when it happens.
Encryption ensures that no one but those with the encryption code hear about incidents on a real time basis. Of course, someone on the "inside" could still pick up the phone and tip a friend on the "outside," but how likely will this happen on a regular basis?
For those of you who don't believe that controlling the flow of information is a concern of law enforcement officials, I share this true story: Approximately six (6) patrol officers of an unnamed police department in Bergen County were deployed immediately following the shooting of Paramus Patrol Officer Rachel Morgan to specifically prevent anyone with a camera from taking photos at the scene of the shooting. The parking lot of PC Richard and Eistien Moomjy was secured by this team at the direction of unknown officials. Tapes of 2-way radio traffic that evening will confirm this statement.