Why is the title tag of this Twitter page in reverse?

Obligatory xkcd: http://xkcd.com/1137/

More details: Reading the source code from the web page, the username is \u202enahtanoJ where "\u202e" means

> RLO | U+202E | RIGHT-TO-LEFT OVERRIDE | Force following characters to be treated as strong right-to-left characters.

See: http://unicode.org/reports/tr9/#Explicit_Directional_Overrid...

The guy's name on Twitter contains the Right-to-left mark[1]

[1] http://en.wikipedia.org/wiki/Right-to-left_mark