May 19, 2005 -- The FCC rules that VOIP carriers will be required to provide enhanced 911 emergency calling service within five to six months; that deadline is later extended.

Feb. 17, 2006 -- Vonage announces that almost all of its customers have basic 911 service and a majority of them has enhanced 911.

May 24, 2006 -- Vonage files IPO at $17 per share; price quickly drops, and was less than $7 this week.

June 2, 2006 -- Lawsuit filed alleging IPO misdeeds. A second shareholder suit soon follows.

June 12, 2006 -- Verizon Communications Inc. files patent-infringement lawsuit.