blocking ports 6588 or 1080 may be a lot helpful, but i would not say about 8080 , 80, 7212, etc cause korean netblocks are auto g-lined in undernet and for those people who cant connect from there need a proxy on these ports.
why i said 6588 or 1080 because there are a lot of open server ranges on these ports.(60% of port 1080 allow port 6588). what i mean by a lot of servers is 3000+ working open servers on port 1080 which can connect more than 3000(minimum) if it hits a weak server in undernet where the ranges are not k-lined. before sanjose was a weak server, happy its gone down hehe.. a lot of abuse was done from this one as most of the proxys were not k-lined.
But in case of 8080,80 they cant do much. maybe users can only load upto 300 or 500. not much so not so big to worry...
but sure these 1080 can be a killer lol.! please do not post below if u think my suggestion is useless. i dont really argue