Even with increased popularity, the Firefox Web browser <A HREF="http://news.zdnet.com/2100-9588_22-5630529.html?tag=nl.e589">won't face as many security problems</A> as Internet Explorer, according to the president of the Mozilla Foundation. Some critics challenge that assumption. Symantec CEO John Thompson and other security executives have claimed that open-source programs will become more vulnerable as they pick up more users, because more hackers will become attracted to it.