5 titles.

1. Law & Order: Special Victims Unit (1999 TV Series)
Episode: Victims (2001)
Just another day on the thin blue line, Detective? You better watch out.
2. Law & Order: Special Victims Unit (1999 TV Series)
Episode: Philadelphia (2007)
I put my head on the chopping block for you two dozens of times, and you hit me with this 'Thin Blue Line' crap?
3. CSI: Crime Scene Investigation (2000 TV Series)
Episode: One to Go (2009)
Guys like us just don't get to hang it up. This job is who we are. We are the thin blue line between order and chaos. You take yourself out of the equation, who knows what's gonna happen. That's the Butterfly Effect. You taught me that. The bad guys will win more if we don't have you. Who is Watson without Sherlock Holmes?
4. End of Watch (2012)
I am the police, and I'm here to arrest you. You've broken the law. I did not write the law. I may even disagree with the law but I will enforce it. No matter how you plead, cajole, beg or attempt to stir my sympathies, nothing you do will stop me from placing you in a steel cage with gray bars. If you run away I will chase you. If you fight me I will fight back. If you shoot at me I will shoot back. By law I am unable to walk away. I am a consequence. I am the unpaid bill. I am fate with a badge and a gun. Behind my badge is a heart like yours. I bleed, I think, I love, and yes I *can* be killed. And although I am but one man, I have thousands of brothers and sisters who are the same as me. They will lay down their lives for me, and I them. We stand watch together. The thin-blue-line, protecting the prey from the predators, the good from the bad. We are the police.
Northbound through the houses. Hispanic male, blue checkered shirt. Zero-head, he's a parolee. He's fucking huge.
Why the fuck did you get married in your dress blues? If you worked at Best Buy would you wear that fucking stupid polo shirt?
5. Life on Mars (2006 TV Series)
Episode: Episode #1.6 (2006)
And they call us the thin blue line.
5 titles.