The thing is, Mozilla & co. probably have quite a few holes as well...but since only 1% or so of all surfers use them, nobody cares to find them all out. Automatic pop-up blocking, tabbed browsing, extensions, themes... the only thing "wrong" with Mozilla browsers (other than a very slight learning curve for backups etc.) is that they're actually standards-compliant so every so often pages written with Microsoft's non-standards-compliant code in mind don't display properly. I just wish Web authors would catch a clue and stop writing in "Microsoft HTML." You'd think more people would refuse to put up with MS's crap just on general principles.