If you happen to get booked by the NYPD, you'll probably be taken back by the gentle kindness of police officers removing your phone's battery “to avoid leakage” while its on you. At first you'll probably feel a strange feeling of gratitude for the thoughtful gesture, but there is more to it than you surmise. According to the NY Daily News, an internal memo instructs police officers to actually remove batteries from mobile phones from those who are arrested and write down the IMEI. From there, it's inputted into a database which would enable law enforcement officials to track phones used by suspects in past, present, and future crimes. Now there are some red flags that come up with this kind of procedure – some argue that is circumvents warrant requirements and goes past the line when it comes to the right of a suspect. So if you don't want the NYPD to get their hands on your IMEI, it's best to stay away from trouble.