Facebook doesn't support HTML, which is sometimes a pain, but overall it keeps the site cleaner (no more hard-to-read custom layouts) and safer (everything ranging from malicious pages to IP logging).

That article was talking about information being given out to advertisers. The original argument concerning safety was that HTML allows people such as hackers to add things to a profile page that could harm you (e.g. grabbing cookies and thus things like email logins) or your computer (e.g. virus).

Of course, I'm not advocating giving personal information to advertisers.