Here is a link explaining What a 419'er is
He violated no less than 75% of my IM rules.
My IM rules are basically sent to anyone who IM's me that I don't know. Within 2 lines they get the URL (which officially will change to a tinyurl ref: http://tinyurl.com/2nprbg)
Personally, there are a couple of things I wish you could do in the IM world:
1) Hit a spam button which gets your IM account and IM's temporarily monitored
2) Auto send a link, document to anyone who IM's you for the first time.
3) have some recourse other than "Block" against abuse.
Just my $0.02 for the day.