[squid-users] Clients running amok - what can one do?

Ever so often we have clients (browsers) that are somehow (?) caught
in a tight loop, resulting in a LOT of queries - one example

7996 10.39.108.198 http://cdn.media.zylom.com/images/site/whitelabel/promo/deluxefeature/button_up.gif

(7996 requests per hour from 10.39.108.198 for
http://cdn.media.zylom.com/images/site/whitelabel/promo/deluxefeature/button_up.gif)

How can I automatically throttle such clients?
I'm either looking for an iptables or squid solution.

-- 
Ralf Hildebrandt (i.A. des GB IT)               Ralf.Hildebrandt_at_charite.de
Charite - Universitätsmedizin Berlin            Tel.  +49 (0)30-450 570-155
Gemeinsame Einrichtung von FU- und HU-Berlin    Fax.  +49 (0)30-450 570-962
Geschäftsbereich IT Standort CBF                     I'm looking for a job!