Oh heavens, I wasn't aware that there was an internet term for it, I truly just meant it as someone who "jumps" in without introducing themselves. Sorry if I have offended anyone, that was never my intention.
Faye I take you point re not knowing if someone has been lurking for a while before joining, but I notice that they will often start with a sort of "Hello I've been looking at the site for a while and have decided to take the plunge and join" type post, and usually then go on to tell a little about themselves.
There have been a couple lately who have joined like that and seem to making good contributions and getting a lot from the site too.
It's the ones that start straightaway with a question and no introduction that sometimes ring alarm bells.