To stop them use a call blocker. It will also stop those groups that are exempt from the DNC List. They're available online and start around $50 or so. http://800notes.com/nb/search?q=call+blockers
ID says "Irvine CA" but NOT Irvine area code. Getting a lot of these "Irvine CA" calls with all sorts of area codes (with the exception of Irvine). They never leave a message. Annoying. Blocked them all. Wish they would find something worthwhile to do with their limited time on Planet Earth.