Massive recalls of contaminated meat in recent months have shaken confidence in the nation's food safety system and raised questions about whether the government should tighten regulations. An estimated 5,000 people die yearly and some 76 million are sickened because of food-borne pathogens like E. coli, listeria and Vibrio vulnificus. Consumer advocates say the government needs to increase inspections of both domestic and imported products and sanction facilities that repeatedly fail safety tests, because new voluntary inspection procedures are failing dismally. But industry officials say increased regulations may put plants out of business without increasing food safety. And while natural contaminants pose a continuing threat, policymakers also have worried since the Sept. 11, 2001, attacks that terrorists could try to sabotage our food supply.