legal selling of email addresses?

I'm based in the UK, I was wondering if someone in the US could enlighten me as to whether selling email addresses is legal in the US? specifically the following:

http://www.lsshost.com/edu.php

I have just been recieved through 3 different email accounts a message advertising this to me including a work one (I work in education so right industry, wrong country) that has up until this stage been spam free. To my knowledge neither myself or the organisation I work for has ever used this organisation...

If it isnt legal, is there any way I can inflict pain (legally of course) on them??

generically speaking, yes its legal. just like selling any non-confidential information. if the original source sold the email address in violation of a privacy policy forbidding it, you would be able to do something with them.

thanks for that, one more specific to check, in the US is it required for user to actively opt out of such things or is it assumed that they have opted out unless they actively opt in??

I realise I don't realistically stand a chance at annoying the company I highlighted in my first post, but if I can find the company who collected and sold the one particular email address that I purposely dont sign up to things with... (totally futile I know, humour me though!)

actually, there isnt really an opt in/out for the selling of email. thats for receiving email. they are currently required to post a privacy policy regarding sharing your information, but if you sign up, you agree to whatever is in it. they can also change the privacy policy at any time

its actually a long shot, as most places that "share" your information have never claimed otherwise. you can certainly complain about it. there are so many ways this end company could have ended up with even a fairly private email, including some kind of random generator, that youd be looking for a needle in a haystack.