The duties of INS as a whole were split by the DHS (Department of HomeLand Security) The INS earlier was responsible not only for approving petitions but also border security.

It's now been split up as USCIS (U.S. Citizenship and Immigration Services) which handles the application portion , ICE (Immigration and Customs enforcement) , CBP (Customs and Border Protection)

Does that mean they are doing a great job? Who knows..

http://www.dhs.gov/dhspublic/theme_home4.jsp