As soon as I passed him (riding at the speed limit) he looked over at me, took off and started chopping lanes, cutting off adjacent cars and not even indicating as they slowed to avoid him.
After seeing him do this about three times I pulled up next to him at the lights for the following verbatim exchange:
Sparks: Are your blinkers broken or what champ?
Squid: Nah bro..
Sparks: Well f#@%^*g use them! You're riding like a total dickhead and making everybody on two wheels look like shit!
Squid:

Sparks: Pull your friggin head in, stop cutting off other people on the road and start riding properly!
Squid:

Sparks:

I am not so self righteous to have a go at him for not wearing gear - even though I am getting sick of picking people and their bikes up off the road where bits of their skin remains attached to the surface, but I really have no patience for people who ride like this. These riders are the reason why I have to listen to people say, "all bike riders are idiots".
So if you see a squid being squiddy, I encourage you to go up and remind them that the rest of the bike riding community does not think they are as awesome as they do.
Quite the contrary really...