Five years ago the majority of local police departments had a negligible presence in social media. They barely posted crime updates or traffic alerts on Facebook or Twitter; many had no social media pages at all.

“Police have always had this trouble: ‘does it tip off the bad guys?'” said Bruce Schneier, chief technology officer of cybersecurity firm Co3 Systems and a fellow for the Berkman Center of Internet and Society. “That’s not just social media but any kind of public relations.”

via Cops harnessing social media’s reach to catch criminals.