iillaa , there is a option "Report to moderator" for each post and best way is to use this option to report plagiarism.What report should contain is link to original post/source and archived post of user you want to report.
In most cases of plagiarism punishment is a permanent ban,but you should keep in mind that there is a lot of reports and that moderators need time to process everything.
A. this is a site copying/mirroring bitcointalk, so reporting doesn't make any sense, and isn't really possible.
B. Reporting a user for plagiarism using the "Report to Moderator" button i believe doesn't do anything. You'll need to open a topic in the meta section of the forum to actually get them banned.
( I believe i read this somewhere where a moderator stated this was the case.)