I know it's always a problem...

Since ice cream trucks (especially the midnight and/or winter ones) are commonly known for selling drugs, it seems like it should be fairly easy for police to bust them. (But in reality, I guess it's probably not so easy)

Here's where they busted one in NY. It says ""detectives began investigating Mr. Jordan after people in the neighborhood told them about his activities"
http://www.nytimes.com/2007/08/04/ny.../04softee.html