alt Hacker Newsthis is a very common pattern in tptacek's comments, but it's not worth calling out as he absolutely refuses to recognize it, always falling back to a similar response you see here.
with a quick google of "3des broken" and reading the first paragraph of wikipedia on 3des, i was able to guess (correctly!) what they original commenter was referring to.
It's pretty self-indulgent of me to respond to this comment, but just real quick: the pattern you're seeing is me in fact not being one of the top-tier experts in cryptography on Hacker News (just one of the loudest), and not knowing who this person is, and not having had a reason to think about 3DES in quite a long time. What you're reading as snark or lawyering is, rather, me meaning exactly what I said, and being uncertain about what that person was talking about.