If a customer on a host runs a script (PHP) that consumes a lot of resources ends up crashing a server because it consumes all available CPU and memory resources on a server that has plently of resources to go around...

does a host or system admin have the right to look at the source code of that script which is authored and copyrighted by the owner to see if it was maliciously made to do just that...crash a server??

Any hosts experience with this situation or similar?

actually any script...but PHP scripts are the hardest to regulate for me because CGI's can be easily limited to memory and CPU seconds...can you do that same for PHP somehow?

You can run PHP as a CGI interpreter just like Perl. I understand there might be a performance hit, but in my experience it is negligible (depends on how you load your server I assume). I found PHP to be lighter than Perl actually, though I still love both :)

Anyway, running PHP as an interpreter will let you curb usage, memory, CPU seconds just like you said.

--edit--

But that doesn't answer your legal question... I too am curious what the legal issues are regarding looking at client's code. I have been fortunate to not have a reason to do so yet. [Perhaps it's a Terms of Service thing. I'm no lawyer, but you could make it a condition that to be hosted on the server you agree that your code may be reviewed.] Regardless, it's too late for your current problem, and once again I find I have written half a page but contributed nothing to this thread...