The MI5 poster: His name is Mike Corley, he is an IT professional but
alas he has mental health issues. Here are some details about Mike
Corley. He lives in London, UK. He first began his postings to usenet,
BBS, and forums in 1995, unsurprisingly first to alt.conspiracy.

He has his own website:http://www.five.org.uk/

"There have been numerous newspaper articles and online thesis about
Mike's postings, this is a BBC article on the subject:"
http://www.bbc.co.uk/dna/h2g2/alabaster/A164404

"And amongst many other covers of the Mike Corley phenomenon there has
been a modern opera about this usenet legend:"
http://www.thecorleyconspiracy.com/

The problem is amplified by posters who reply to Mike's X-post floods
without snipping, and without removing the crossposts. But also Mike
Corley sets "follow-up" groups to his MI5 posts, this is where he
hasn't actually posted to a specific group but it's listed as "follow-up" in
the crossposts, the users who reply, their posts show up in groups
that Mike wants flooded. Mike Corley has set uk.misc as follow-up to all
his posts, (which I've removed)it gets flooded with the replies, and of
course the X-posting. Mike Corley has been doing this since 1995, and
he knows what he is doing, he avoids killfiles/plonk/block by morphing
and using pay-as-you-go dial-up. Filters rarely have an effect as in this
example, if you set the criteria as "MI5",
then the flood morphs to "MIfive" or whatever. He doesn't post via
google despite the headers, nor are the email addies valid, he dances
between proxy servers such as altopia etc, filtering has no effect.
The simple rule with Mike Corley floods is to ignore and not to reply.
Mike will take his medication and eventually stop.....until the next time.
But if users do the foolish and reply/x-post/fail-to-snip, then Mike
Corley sticks around. So don't spam your pointless replies across
dozens of groups.