I run an exit node, and as such, I get abuse emails like this from time to time: https://lists.torproject.org/pipermail/tor-relays/2015-October/007982.html
Mostly I ignore them, but since their automated report contains the sentence "Please feel free to send us your comments or responses.", every so often I send something to complain about their practices. To my surprise, apparently somebody does actually read these because today I got a reply.
I'm not reproducing the entire response here without permission (they seem kinda touchy), but the person that replied did mention that they have some kind of rbl "in beta" regarding tor exits. They seemed to imply that doing so was quite a burden on them, though, which I don't really understand (IME blocking tor exits is easy; intentionally so).
I'm trying to keep the conversation going, but I was wondering if anyone from the tor project has tried to reach out to them in some kind of official way? I'm just some random guy, so I don't know if it would be preferable for someone more knowledgeable, or with more access to tor infrastructure, to be conversing with them. (e.g. teor)
I assume some people will say this isn't even worth the effort; it's not like it's hard to just ignore those reports. But it doesn't take much effort to just try to talk ot them, and it perhaps helps to give tor a reputation of cooperation and helpfulness.