NY Daily News 
Friday, Oct 9th, 2009
The NYPD is amassing a database of cell phone users, instructing cops to log serial numbers from suspects’ phones in hopes of connecting them to past or future crimes.
In the era of disposable, anonymous cell phones, the file could be a treasure-trove for detectives investigating drug rings and other criminal enterprises, police sources say.
“It’s used to help build cases,” one source said of the new initiative.
“It doesn’t replace the human element, like debriefing prisoners, but it’s another tool to use that we didn’t have in the past.”
A recent internal memo says that when cops make an arrest, they should remove the suspect’s cell phone battery to avoid leakage – then jot down the International Mobile Equipment Identity number.
The IMEI number is registered with the service provider whenever a call is made.