MIT–Harvard police radio
Fifteen Harvard, MIT, and Cambridge police channels have been rebroadcast live from this site since 2005. Listen in to transmissions from dispatchers and patrol officers and Securitas security guards
... in streaming MP3 format on MIT Crime Club Radio, http://radio.mitcrimeclub.org:8000/listen.pls
Update. MIT Crime Club Radio WIGGUM went off the air in August 2016.
MIT Crime Club