Please pardon the interruption.  If you manage the APEWS list, please contact us.

just a few more details. APEWS appears to use our "top sources" list http://isc.incidents.org/ipsascii.html as a blocklist. This list is an unfiltered list of sources for which we received a lot of reports. It is not supposed to be used as a blocklist as it is bound to include false positives. In addition, APEWS turns these /32 listings into /17 blocks, and they appear to violate our "Creative Commons Share-Alike License". Sadly, all other attempts to contact them have failed.

APEWS may be a useful "anti-spam" list if you do not mind losing a lot of valid e-mail as well. For example, right now, it appears to block the entire AT&T network.