Can one prevent a co-author from publishing on arXiv without consent? This is very much related to a previous question I posted here: How can one prevent a co-author from publishing without consent? It is not the same question though.

Consider a situation where a co-author submits a paper without your consent to arXiv. This seems to be more problematic than them submitting it to a journal, because on arXiv it is published (almost) immediately and there does not seem to be an easy way to stop it, and also arXiv does not ask about consent from all co-authors.

It does not seem to be illegal to do this because the co-author has copyright as well and so it seems that legally they could grant a non-exclusive license to share the work. However, it does seem to go against the principles of academic honesty to publish without the consent of all co-authors (and that would include IMHO publication on a non-refereed source like arXiv.) 

It does not seem possible to remove papers from the arXiv.

The question is then if there is a way to prevent it beforehand. Assume the co-author is not malicious, but simply a bit slack, so they would be willing to cooperate after it is found out (though if there is a way to prevent even malicious actors from doing this that would be even better).

If it is not possible to prevent it, is it possible to remove one's name from an arXiv article if one does not endorse the paper submitted?

I am aware that the best means is having a good relationship and communication with the co-author in the first place, but I would like to ask what other practical means there are.

To show this is not a completely made-up scenario, here are two examples of papers withdrawn from the arXiv due to this issue: http://arxiv.org/abs/0810.4310v2 and http://arxiv.org/abs/1307.4296
Once an author has put their work into the public domain, it is very difficult to rescind it. All of the authors still have rights to the works, like attribution or trademark, but not copyright since that was given up as part of uploading to arXiv. So it might be impossible to force arXiv's hand with any legal tool where both of you are co-authors of the works. You do have one option though, but it's not pleasant...

If the co-author claimed joint-ownership over some part of the paper that you can prove (or they will agree) that they do not have rights to, then the works was illegally shared with arXiv, and arXiv have a duty to take it down if you DMCA it. The key is that you have to be sole owner of the copyright, and not shared ownership. Since you never personally signed off on the publication, that should be fairly easy to put forward. I don't know what arXiv says about this though, since their may be a fee for the co-author for retracting the paper - which I suppose you could both share, and i think you should, since arguably you should have done more to prevent a communications error like this ever arising in the first place.

Finally, may i just add, that this would not be illegal, but it would go against the principles of academic honesty...