Trend are a bunch of idiots who dont understand networks or the chaos they cause
They tried this a few years ago and it affected my company and all of our clients. they listed the range 18.104.22.168/16 as a source of spam. My company is a small UK ISP, and we have a range of 1024 ip addresses in that range. Trend refused to talk to us because we were not from InterCard, a German company who owns 22.214.171.124 to 126.96.36.199. Being totally unable to comprehend that the /16 range was split into lots of /22 networks or smaller Trend just blocked an arbitrary range plucked from their arses. We had over 200 clients unable to send mail.
Despite offering to send them through all the information from RIPE, they still refused to listen to the fact that intercard did not own the whole /16 range, so I emailed TheRegister, and was soon speaking with Dan Goodin. Trends defence was "you are in a bad neighbourhood on the internet" my reply was "you are allegedly a reputation service, if my neighbour has a criminal record, does that mean i must have one as well? as that is what your reputation service is insinuating with this blanket ban of addresses". After an hour or so of back and forths, someone who was in charge of the company braincell realised they screwed up and removed the block that they initially said would take a week to remove!
I will never recommend the use of Trends services to anyone for anything, i wouldnt touch them with a stolen bargepole.