NVK's claim that I read was that someone was infringing on the specific trademark blockclock. Trademark does not cover a process, nor a copyright. It appears that BTCclock created a competing product with original authorship. He mentions that he didn't reverse engineer a blockclock, but even if he did, that's perfectly legal within the DMCA. Copyright and trademark do not protect the duplication of an idea. So either I misread NVK's statement that his actual trademark was being infringed upon and he implied that that trademark was specifically "blockclock", or he is not acting in good faith.
While I sympathize with the argument that trademark law requires enforcement, Blockclock is such a generic name that a trademark should have never been issued. Equally, displaying Bitcoin data like block height on a screen is an obvious idea that certainly doesn't deserve protection.
Notably, the term "btcclock" was coined 7 years ago by rcassata, for essentially the same idea: https://github.com/eternitywall/btcclock
There's nothing wrong with another project choosing to use that generic name for yet another implementation of the same idea. Coinkite should do the right thing here and withdraw their takedown.
Discussion
NVK clearly indicates the trademark he is protecting is for "blockclock" by boosting the following post.
NVK implies he is using his trademark claim to protect his sales of his luxury-priced BLOCKCLOCK. This does not appear to be a valid a trademark or copyright claim.
This can be publically resolved with the simple gesture of publishing the actual takedown request sent to github. If NVK holds a trademark for BTCclock, then he has a positive legal right established in law by means of the monopoly of the use of force and people with guns and cages. If NVK only holds a trademark for BLOCKCLOCK, and he does not publish the takedown request, then we can assume he is standing behind the 5th amendment.