This website showcases good deeds done by people who listen to police scanners. Info is listed by date of occurrence.
Please see "2006" (Tyler Texas) and "April 2013" (Watertown Mass) for the best stories. Also see Jan 2013 for the capture of bank robber near Carson Nevada. Feb 2014 - another bank robber busted - this time in Queens NYC.
Please also check out the ' sonofrcma ' or ' firerad2 ' lists at yahoogroups - you can use the keyword "openness" to find many more good scanner stories there
http://www.radiobanter.com/search.php?searchid=58897 - many openness posts here
https://sites.google.com/site/sonofrcma/ - Legalities of Scanning - Ethos of Scanning
http://forums.radioreference.com/virginia-radio-discussion-forum/191875-moral-dilema-2.html - Will online feeds kill the scanning hobby?
Odds and Ends
Kidnapper busted by scannerist - see the public comments - http://www.tulsaworld.com/news/article.aspx?subjectid=318&articleid=20120505_78_A15_BOEROe845115
There was a tow truck driver in Scranton PA IIRC (maybe Wilkes Barre Pennsylvania) that busted a couple of people during police chases - rammed them with his truck or held them at gun point - circa 2004