There was a period where Hacker News consisted primarily of people on the right-hand side of the spectrum. People who were working inside of startups or had lots of experience with the web and our industry. Pretty much everyone knew what sharding was, and MongoDB wan't very popular.
These days we've got a lot more people and they show up all across the board.
Clearly if this is on the homepage, it was voted there by your peers. This kind of knowledge is completely obvious to many of us, but not everyone is on your level. Cut 'em some slack.
i'm just not so sure if the direction this is heading to is good. and also the headline of that article is miserable (as omarchowdhury already pointed out).
Hmm, I thought people mainly knew about this. But I researched this a lot while making http://2fb.me and actually witnessed this myself with google docs but didn't think twice about it. I'm sure the same thought was going through the heads of everybody reading this that knew anything about how the Facebook sharer worked. For those that found this news, it's beneficial to put open graph meta tags on your pages to control the crawler and you can also invoke the crawler (http://developers.facebook.com/tools/debug) when your page changes before Facebook updates it automatically every 2 weeks or so.
These days we've got a lot more people and they show up all across the board.
Clearly if this is on the homepage, it was voted there by your peers. This kind of knowledge is completely obvious to many of us, but not everyone is on your level. Cut 'em some slack.