> Oh, and did you know that with modest, low volume channels (>200 <1000, some networks tolerate more) you can make IRC networks struggle? Turns out that their lousy distributed design hurts more than helps when single channels get heavy.

source? or at least names of networks/IRCds?

freenode at least has 19 channels with more than 1000 users currently, and one with just barely more than 2000.

##linux 2072 :It's official! We're now Linux.Chat! | Channel website: http://linux.chat | Pastebin: http://paste.linux.chat | Spammers or trolls? use !ops <troll's nick> <reason>". | For op assistance, join ##linux-ops | Feel at home and enjoy your stay
#ubuntu 1798 :Official Ubuntu Support Channel | IRC Guidelines: http://ubottu.com/y/gl | IRC info: http://ubottu.com/y/irc | Pastes to http://paste.ubuntu.com/ | Download: http://ubottu.com/y/dl | Currently supported: 12.04 LTS, 14.04 LTS, 15.04, 15.10
#python 1763 :Don't paste, use https://bpaste.net/+python | http://bit.ly/psf-coc | NO LOL | Tutorial: http://bit.ly/MCAhYx | New programmer? http://goo.gl/c170V | Specify 2.x or 3.x in your question | Find your local User Group: http://goo.gl/S1Zsq | #python-fr #python.de #python-es #python.tw #python.pl #python-br #python-nl #python-ir #python.it #python-ro #python-india #python-hu #python-dev
#debian 1707 :Debian 8 Jessie released! /msg dpkg jessie ; /msg dpkg wheezy->jessie ; /msg dpkg install jessie | current point releases: /msg dpkg 8.2; /msg dpkg 7.9 | NO FLOOD: /msg dpkg paste | /msg bots NOT people | offtopic: #debian-offtopic | testing/unstable: #debian-next (irc.oftc.net) | chanlogs: /msg dpkg irclog
#archlinux 1655 :Welcome to Arch Linux World Domination, Inc. <+> Be kind to the people who are helping you. Be kind to the people you are trying to help. <+> FOSDEM 2016 participation! https://lists.archlinux.org/pipermail/arch-events/2015-October/000544.html <+> Yes we know about Twitch
#freenode 1566 :Welcome to #freenode | tor-sasl is offline until further notice | Staff are voiced; some may also be on /stats p -- you can /msg us at any time | FAQ: https://freenode.net/faq.shtml | Channel guidelines: https://freenode.net/poundfreenode.shtml | Blog: https://blog.freenode.net | Be nice!
#haskell 1505 :http://www.haskell.org/ | https://wiki.haskell.org/IRC_channel | Paste code/errors: http://lpaste.net/new/haskell | Logs: http://tunes.org/~nef/logs/haskell/?C=M;O=D http://ircbrowse.net/day/haskell/today?mode=recent | http://reddit.com/r/haskell | Administrative issues: #haskell-ops | Hackage status? http://status.haskell.org | http://downloads.haskell.org
#Node.js 1252 :Can't talk? Get registered on freenode (http://freenode.net/faq.shtml#nicksetup ) | Current Stable v5.0.0 (LTS: Argon v4.2.1) | Mission Statement: http://bit.ly/node-irc-mission-statement | Info: http://nodeirc.info | Logs: http://logs.nodejs.org/node.js/index | On codes of conduct: http://j.mp/1RFlyvr http://blog.izs.me/post/30036893703/policy-on-trolling
#go-nuts 1242 :isgo1point5.outyet.org | golang.org | known issues: golang.org/issue | channel log: botbot.me/5/log | don't ask to ask; just ask | ʕ◔ϖ◔ʔ | gophercon2015 videos: https://goo.gl/vKWB3Q
##javascript 1207 :Can't talk? Get registered on freenode (HOWTO: http://freenode.net/faq.shtml#nicksetup ). | ECMAScript, JavaScript. JS *not* Java. | Say "!help" (or ask and wait). | Say "!mdn abc" for docs on "abc". | Don't paste code in the channel.
#git 1169 :We use git, but don't be a git. Help given and wanted, or just gorge on candy | Current stable version: 2.6.2 | Start here: http://jk.gs/git | Getting "cannot send to channel"? /msg gitinfo .voice | Beware the git-reaper this Hallow's Eve: he comes for your rebases
##security 1152 :Computer & Physical Security http://fnsecurity.org/ http://ow.ly/gsVTo | Type !op to summon staff - Be nice or GTFO. -- Toothe is seeking his stalker from a security presentation on Oct 27!
#bitcoin 1126 :Current v0.11.1 | DO NOT POST ADDRESSES | uPnP vuln: https://bitcoin.org/upnp-vulnerability | https://bitcoin.org/ | bitcoin.com is SCAMMY | https://en.bitcoin.it/wiki/Faq | No pricetalk (#bitcoin-pricetalk), ads, trading (#bitcoin-otc), begging, altcoins | Web wallets will probably steal your money | URLs are often MALWARE
#ansible 1123 :Ansible - http://docs.ansible.com *** 1.9.4-1 has been released - https://groups.google.com/forum/#!topic/ansible-announce/r_uNM1lWlAE *** Ansible 2.0.0 beta 2 is ready for testing - https://groups.google.com/forum/#!topic/ansible-project/krpeTwi3mpo
#gentoo 1103 : Gentoo Linux Support | Can't speak? /j #gentoo-ops | long pastes: dpaste.org | masked by license? http://x.vu/WgxYLs | | Unworking hibernate and suspend? emerge -1 upower-pm-utils | firmware not loading? http://goo.gl/MzVLBN | perl conflicts? http://goo.gl/n1FMk8 | Be nice! http://xrl.us/kftd
#bash 1082 :FAQ: http://mywiki.wooledge.org/BashFAQ | Guide: http://mywiki.wooledge.org/BashGuide | Ref: http://gnu.org/s/bash/manual | http://wiki.bash-hackers.org/ | http://mywiki.wooledge.org/Quotes | Check your script: http://www.shellcheck.net/ | Mailing list: https://lists.gnu.org/mailman/listinfo/help-bash | Devel: http://xrl.us/bmodjy
##networking 1074 :Computer Networking | If you have a question, just ask it! | Please don't paste - http://paste.debian.net | M = mega = (10^6). m = milli = (10^-3). Mi = mebi = (2^20). B = bytes. b = bits. | Vendor Help = #$vendor | pastebin iptables-save | Why aren't you using IPv6 yet? | IP address classes died in 1993 | VPNs were not designed for anonymity https://goo.gl/iLyXUP
#vim 1050 :Can't Talk? Get Registered on freenode (HOWTO: http://ur1.ca/90niw) | Vim 7.4.900 http://www.vim.org | Don't ask to ask! | Use :help and :helpgrep | WIKI: http://vim.wikia.com | PASTE: http://vpaste.net/?ft=vim | DONATE: http://www.vim.org/sponsor
#puppet 1000 :Puppet Enterprise 2015.2: http://puppetlabs.com/puppet/whats-new | Puppet 4: http://bit.ly/1fCLbPX | Help: http://{ask,docs}.puppetlabs.com | Beaker users read this! http://bit.ly/1zE2DYU | Bugs/Improvements: https://tickets.puppetlabs.com/ | Logged http://bit.ly/11ifvbU | Community guidelines: http://bit.ly/1wTNy65 | PuppetConf Videos http://bit.ly/1NWiHQb

now, the volume of chat may be too much to read for some people, but that's not an issue with the protocol.