Tracking an ip that shows regional address

How do you do it?

[walrus]

I have noticed some bad behaviour on my site and because i use Adsense i am trying to be vigilant and block any nasties.
The other day my logs showed one ip grabbing
files and folders in a stange way.Definitley malicious,i figure someones trying to sabatoge my Adsense or stealing or copying content.Anyway my logs only shows for example hse-toronto-ppp123824.sympatico.ca. which is the same for thousands of sympatico users in whatever area code that applies to.
When i ask Sympatico for help to track it they say i need to open an official investigation with the police because (though charge them with what i dont know)they can not provide info on which customer it was so at best i can have their account closed.
I notice Webmaster world uses some kind of script to welcome me with the actaul ip so i know i could probably find script that would do that,logs the ip somehow and then i'd be able to see it.
But as far as i understand , like my ip it changes every time i connect so how could i block them without adding deny from hse-toronto-ppp123824.sympatico.ca. to my htaccess and blocking thousands?

Any idea?
Thanks

[Sanenet]

But as far as i understand , like my ip it changes every time i connect so how could i block them without adding deny from hse-toronto-ppp123824.sympatico.ca. to my htaccess and blocking thousands?

Aye, that's the rub. AFAIK it can't be done, you're blocking the IP range.

The hse-toronto-ppp123824.sympatico.ca isn't the IP, it's the proxy range of sympatico. If this chaps on a dialup dynamic IP, you can't block him and him alone.

Best bet is to make sure whatever he's doing isn't detrimental to your server.

[walrus]

Thanks,
I was afraid of that.