Is it possible to have a paper removed from online proceedings after it has been published and the conference taken place? The basis is, that I did not consent (nor was it sought) that the paper be published. It was not even presented but still published. Do I have to take the legal route? All I want is the paper removed from the online repository. Anyone ever seen this happen, anywhere?

Agree with first step above.

Key question is what terms and conditions did you agree to when submitting! Who now owns the copyright?

sorry for the absence. it appears that I will now need to do this.

@Hugh, that is probably what I was going to do. email the organisers of the conference and request them to remove it (but i believe I would need to give a reason out of courtesy, and they certainly wouldn't remove a paper just because i said so, given the situation described below). if they don't comply, i might need to get a lawyer involved. if anyone knows of a US based lawyer that might be suitable and experienced with this kind of thing plz PM me.

@Thesisfun, the issue I have is that I personally did not agree to, or see any conditions when submitting (because I didnt submit the paper). I believe the conference only requires one signature and that person is responsible for having the consent of all submitting authors. I believe normally this is the normally the first author, but in this case it was the 2nd, my supervisor. My supervisor was also program chair and is heavily involved with, and has a history at the conference. This would be why my supervisor believed they could 'get away with it'.

Just to add, the paper actually wasn't even presented at the conference but somehow managed to remain in the proceedings. Despite being told that this is not what is normally done.

I'm assuming that you've already fallen out beyond repair with your supervisor? If not, employing a lawyer seems the fastest way to make that happen. Which if you are in the US will almost certainly have professional consequences for you, given the importance they seem to place on the letter of recommendation from your supervisor for job applications. I'd be careful not to torpedo your career in anger. And are you sure that there are no emails that you forgot to reply to, suggesting submitting the paper that your supervisor could produce as proof of assumed consent or anything like that?
Normally graduate students are quite pleased to get a publication. What's so bad about the paper being published in this place? Is the conference so poor that it's a minus rather than a plus for your cv? I'm not in a field that does conference proceeding but I know for comp sci for instance that a conference proceeding can be a good publication. Or have you found a bad error or something like that? If it's the latter getting your supervisor (given the professional embarrassment for him/her too) to negotiate replacing it with a corrected version might be a better path.

When you say the paper was published without your consent, do you mean your supervisor submitted your work without your name on it, e.g. they have plagiarised? If so I would think your university would have procedures for serious misconduct like that, so it might be better to speak to someone there before engaging a lawyer at your own expense?

If your name was on it, this seems a bit of an over-reaction -- especially if you would have consented if you had been asked, and are just so angry about not being asked that you're prepared to throw away a publication credit you would otherwise have wanted. Losing the publication will probably hurt your career more than your supervisor's (as will taking legal action against them).