1. I do not have time to do a full Twitter shiur on the halakhot of Mesira/Informing. However, for all those seriously asking why @jacobkornbluh is not a moser I will answer briefly as follows:

First, the act of journalism is not the same as "giving over" to authorities

2. Second, even regarding turning people in, there are qualifications. See these quotes by R. Hershel Schachter, the second one of which is linked below. I would consider flaunting health codes a "public menace"
http://www.torahweb.org/torah/special/2007/rsch_mesirah.html

3. For those who have the time, @TorahWeb has a 45min shiur by R. Hershel Schachter on, "Should I Call the Police? Clarifying the Issurim of Mesira and Chilul Hashem"
http://www.torahweb.org/audio/rsch_120306.html