Regarding all this crap coming from ComCast:

http://www.spews.org/html/S2963.html

Poster child of how not to run a broadband network company
when it comes to dealing with abuse.

1) Don't reply to abuse reports.

2) Let abuse@ mailbox overflow.

3) Announce IP ranges not assigned (or purchased?!) from
ARIN and let spam flow from there.

4) Have representatives who tell inquirers it can take
days to shut down spamming or DoSing cablemodem
accounts.

5) Tell their own customers "we take the spam issue seriously".

6) Become, in a matter of months, the worst spammer-abused
networks on the internet. On par with some entire large
nations as far as spam flow goes!

http://www.spamhaus.org/statistics.lasso

Top 10 Worst Spam ISPs
December 2004
1 mci.com
2 kornet.net
3 sbc.com
4 chinanet-cq
5 comcast.net
6 xo.com
7 interbusiness.it
8 level3.net
9 crc.net.cn
10 verizon.net

Comcast SBL Listings

Comcast currently has 98 SBL entries, dating as far back as October of 2002
which include 10 ROKSO spammers. Apparently, spammers have immunity on
Comcast's networks.