For years people have often referred to big networks being those with more than the magic 100,000 concurrent users. There's only four networks that currently achieve this and only 5 that have ever achieved it to my knowledge. If you put Dalnet out of the picture because of their previous problems with crippling attacks you'd then include Quake, IRCnet, Efnet and Undernet. Two have no services at all and the other two have a limited set of services which come nowhere near the functionality of Dalnet-compatible services. So I guess using the word "most" is not necessarily accurate but to spend time disputing it is not productive and amounts only to a very small technicality.
