Menchi-
Some people consistently move passages (usually the entire article) of copyright violations to Talk pages. Talks may not necessarily be considered Wikipedia proper. But they are still integral part of Wikipedia operations nevertheless.
This such behaviour acceptable?
Depends on the length of the infringed text. It is completely legal to quote one or two paragraphs from a copyrighted work under virtually every jurisdiction, although such quotes should be clearly recognizable as such. However, copying an entiry copyrighted article to the talk page is not acceptable, since the talk pages are google-indexed. In that case, please blank the page. (Which raises another issue, namely copyright infringements in article histories. That could be addressed, if necessary, by implementing a deletion feature for individual article revisions, which would actually be relatively simple to do.)
Regards,
Erik