But there are two applications: the first is breaking in to a system under some very obscure set of circumstances that you are very unlikely to encounter in the real world. The second is to bump up your karma on HN.
If you do know, then you also know md5 being broken is really really old news.
Seriously. Cryptographers have been warning that md5 seems weak since 1996. There are probably people reading this thread who weren't even alive yet. (It got totally broken in 2004 but the warning signs were way earlier).
Such security! Much wow!
Is there any way to use HN karma? Like, can I sell my account on some shady exchange like people sell big twitter accounts? And if I can, what's the going rate for internet points these days? Asking for an unscrupulous friend.
Nothing other than vanity AFAIK.
It's actually a bit of a scam because karma accumulates and never expires. I've been on the leaderboard for a long time, not because I'm making particularly valuable contributions (I only post a few times a week) but just because I've been on HN since it launched.