You're certainly correct in that obtaining an IRC hostmask is easier than obtaining an IP address. However, in my opinion, the difficulty of obtaining whatever OOC information a group is utilising towards IC oppression is entirely irrelevant. Whether a reroller is identified and subsequently persecuted via common email addresses, photobucket accounts, IRC hostmasks or IP addresses, it is still inherently wrong. It is rather ironic, too; those that employ these OOC tools are also usually the first to have their jowls flapping in righteous indignation over anything that could be construed as an 'OOC attack'.