I see no evidence to suggest that his entire ISP or IP block have been Klined, it's quite possible it is aimed at him solely, and one of those reasons could be due to the fact that his IdentD matches that of a known virus pattern. Many networks, even big ones, have detectors which will auto-kline people matching those patterns. Alternatively, it could be because of the reason I outlined and the person is actually infected.
That said it is of course possible that it IS his ISP/IP block Klined, however, it cannot hurt to follow the advice me and Raccoon gave
BTW, whether you intended it or not, your comments seemed to be laughing at and/or shrugging off our advice which is not nice