hello, is there anyway to limit each script by the owner of the file?

i have free hosting, and the only way i could see that one script is run by one user and another by another is pathname which contains username and owner of the file

i want to stop people doing fork bombs... there are limits on each php script, but that doesnt help me if there are like 10 000 scripts run every second.

apache and php are running on same username - www-data. i can't run them on seperate usernames. but i would like to see somehow that if someone runs /home/user.domain.com/script.php and for example there are like 1000 of these scripts in memory, i can somehow block them

any idea how to do it? i'm using apache mpm worker ran as mod_fcgid

i have script that runs php:

export PHPRC
exec /usr/lib/cgi-bin/php4

so, maybe i could use some other FCGI viariables? or make some small script that will check something?

it has to be efficient though, i have many hits