It's not clear how trademarks would apply here. I can write "General Motors". I can write about General Motors. I just can't impersonate General Motors or their products. That's trademark.
That was my point. GP mentioned trademarks for no reason and I said that the DMCA is a copyright law (that's what the C stands for), and that trademark law is irrelevant to this discussion. I also agree that even if trademarks mattered in this case, it still wouldn't be infringement.
On the other hand, it looks like it was an improper use of the DMCA because they're claiming that EasyList is an anti-circumvention tool (effectively arguing that it breaks DRM).
I believe you can trademark a domain, but trademarks are irrelevant to this discussion. The DMCA is a copyright law. The key questions are:
a) Can you have copyright over a domain? (According to https://copyright.gov, no)
b) If you could, would having a list of them constitute fair use? (Almost certainly, otherwise all search engines would be illegal.)