n. The fallacy of supporting a proposition by inundating one's opponents with specious arguments that are too numerous and too lengthy to read, much less refute point-by-point.
2015
See? This is what I'm talking about. A couple at best tangentially relevant items that certainly didn't merit lengthy quotes. Argumentum ad tl;dr.
2014
The author of the article wrote a long anti-feminist screed including link after link after link to other anti-feminist, argumentum ad tl;dr screeds, cited studies in which the researchers' conclusions were either taken out of context, ignored completely, or just made up out of whole cloth.
2012
Why don't you ever try to quote your arguments, or paraphrase the gist of them? Why do you just place cryptic links full of wordspam agreeing with your world-view? … Argumentum ad tl;dr basically means you're burying your opponent in reams of text that could meaningfully be expressed in a few sentences.
2012 (earliest)
look at http://rationalwiki.org/wiki/Talk:Cold_fusion … perfect example of argumentum ad tl;dr, sneaking gotchas into a wall of text - a written Gish gallop
The verbal equivalent of argumentum ad tl;dr is a debating technique called the Gish Gallop, named after the creationist Duane Gish, who was famous for overwhelming debate opponents with a torrent of arguments too numerous to refute. Oh, and the tl;dr part? That's shorthand for "too long; didn't read," which online folks have been using to summarily dismiss each others' arguments and posts since at least 2003.