An anonymous reader writes: I have, for a while now, been collecting IP addresses from which email spam has been sent to, or attempted to be relayed through, my email server. I was wondering if I should publish them, so that others can adopt whatever steps are necessary to protect their email servers from that vermin. However, I am facing ethical issues here. What if the addresses are simply spoofed, and therefore branding them as spamming addresses might cause harm to innocent parties? What if, after having been co-opted by spammers, they are now used legitimately? What do Slashdot contributors think?