This, and this sort of thing in general, are why I'm not very enthusiastic about security on the web. Facebook and Google can avoid security holes like these,

This, and this sort of thing in general, are why I'm not very enthusiastic about security on the web. Facebook and Google can avoid security holes like these, sure. Perhaps you will too -- that is, you'll avoid this particular one. What about the fifty others, subtly interdependent sources of security problems?