hi Ricky,
i have block the all ports like 80 1080 8080 5000 5001 5010 5050 5100 in my acl and deny this acl and don't replace http port to 8080 it is still 3128. both messenger msn and yahoo block by these ports but if any client use port 3128 as a proxy in yahoo messenger then yahoo messenger is activate. so how i can restrict this port, because port 3128 is also use in browser (Lan Proxy setting ) to web access.