Why do people go to the effort to fill in a contact form with crap?

I just got this contact form response from my "Custom Script" form.....

>>

To Paul,

Here are the results of the contact form submission:

Full_Name : awa nise
Email_Address : awz6@yahoo.com
Website : http://www.sex.com
Ideas : i need some sexxxxxx photoes for some naked girles and naked womenes thank u

<<

Clearly this person is either mentally disturbed or a pre-pubecent teenager.