To be fair to Zidane, from what I have read, the Italian player really said something quite bad to him. That said he should not have done what he did.
Here are some more links to sites relating in their own way to the incident
http://zidanewantscandy.ytmnd.com/ http://francefighter.ytmnd.com/ http://neszidane.ytmnd.com/ http://emca.ytmnd.com/ http://zidanedeathstar.ytmnd.com/