Technical editor changed author order of the paper Recently, I attended a conference as a corresponding author of a paper with five authors. After the paper was published in the conference proceedings, I realized that the technical editor changed the authors order by grouping them according to their affiliations. Is this acceptable?

I feel a bit responsible to my coauthors (being the corresponding author) even though this publication style also affected other papers in the proceedings. But what should I do?
Is this a field where author order is assumed to matter (e.g., applied CS)? If yes, this is completely unacceptable. If no, it is still very strange, but maybe not a big deal in the end. I can only imagine that your paper was handled by a very inexperienced technical editor who is simply not aware that the order of authors is not just a stylistic question, but actually has CV implications (in some cases, at least). 

One way or another, you should get in touch with the organizers of the conference (e.g., the publication chair if they have one, the general chair if not) and let them know. Maybe it is still possible to fix this, but at least the responsible people should be aware of this issue.