I have to say I hold my hands up and am as guilty as charged. Sometimes I can't help myself but to come out with the odd comment and run.
I find some hijackers really funny, some are very clever and whipping in and out so quickly that you don't even know they had come and gone!
Other hijackers I feel just like to butt their noses into someone elses conversation, if seems they like to be noticed without contributing much to a paticular thread.
Others I sometimes feel are there to stoke a fire and stand by to watch the embers ignite.
Others pop in and out to keep the peace a bit like community policeman.
others do it as a form of flirting!
So come on are you are regular hijacker?
Why do we do it?