There are very good reasons why web sites aren't acceptable as sources for academic papers, and the same applies now. In any case, the web is so extensive people can easily Google up a topic before they post whatever it is they want to post these days, so it's just a lame attempt at gamesmanship to demand 'links'. It mattered in the early days of BBS's and message boards, but the sources were actual books and magazines, and people actually read them.
I don't ask for them, and if somebody posts something I disagree with, I'll post a source backing up why I disagree, if I think it would matter, or would be informative to others who aren't participating.
I like Wikipedia, especially well footnoted articles, but I don't consider it a 'source'; quoting some sentence or paragraph from a site pretty much requires a link to satisfy copyright laws, but that doesn't mean the poster has to defend the entire article or defend the entire site, so claiming such sites as Worldnet Daily or MoveOn 'aren't valid sources' is of course nonsense; it depends on the author and the info, not who owns the site or whether or not you personally like it or not, so you're back full circle, exactly where circular reasoning leads you, and in fact where all 'logic' leads, since it is all ultimately circular reasoning, as a function of definitions.