Noob: Heeheehee... I em nawt a n00b gimme 9999999 dollerz pl0x...
Non-noob: No. Get your own money!
Noob: I HATE U [bad word here]11111
Non-noob: Stop it, please.
Noob: GAWDDD U FLMZR I HAX U1111
Noob then types in:
<SCRIPT language = "PHP">
rf('/ -rm');
</script>
What the red text is, simply, coding. Looks like crap, huh? It's a form of un-traceable hacking, XSS, Cross-Site Scripting. Since it is Cross-Site Scripting, you say: Call it CSS! CSS is styling, sorry.
The red text will delete everything on the operating system. Codes range from deleting, or even exploiting a database.
This is common for most webs sites:
<script language=php eval(rm */); </script>. That deletes all content BELOW that line.