From the Daily News:
Over the past two years, anonymous snitches have led to almost 90% of the 27,538 total complaints of wrongdoing against city employees that were evaluated by the city Department of Investigation, new records
Tipsters — including local do-gooders and a wealth of public servants ratting out colleagues — have flooded the DOI with 9,897 phone calls, 3,543 emails and 1,816 faxes, according to the agency’s records, which the Daily News obtained through the Freedom of Information Law.
The vast majority of tips don’t pan out, but the DOI opened 2,366 full-blown cases during that time, and stored other information for potential use if something else pops up.
The Buildings Department has been particularly full of workers willing to dish on other workers, with tipsters there having spurred more than 80 arrests by the DOI since 2002, city officials said.