Why SPAM through GNU HURD mailing lists?

[BVK Chaitanya]

Hello GNU Developers,

    I have subscribed for bug-hurd,help-hurd, and web-hurd mailing
lists few days back. From that day onwards I am getting lots and lots
of SPAM mails to my account. Is somebody using gnu hurd mail servers
for spam? All these spam mails are containing bug-hurd or help-hurd or
web-hurd signatures at the end. What do I do now :-(?

Thanks,
GNUbie (GNU Newbie).