Probably all students try to solve assignments with as little effort as possible -- they collaborate, they look for avialable solutions in the Web, they ask others for help. If it comes to larger tasks like writing a semester paper, a thesis, or a dissertation, some students sometimes even copy text from other publications without giving credits to these authors. This is called plagiarism.
In Germany, there had been some major issues discussed in public over the last couple of years: The former minister of defense had to resign, because his doctoral dissertation was found to be full of texts not written by him. The former minister responsible for education at schools and universities had to resign, because she forgot to correctly mention the sources she used. And there had been other cases as well, all following the same pattern: someone reads a dissertation or thesis of a politician, raises some questions, the politician denies, the public starts looking for evidence, and in the end the politician has to resign and loses the academic degree or title associated with this thesis.
Now, one of the candidates for the election to the city government of Zurich is accused to have plagiarized in a Master's thesis.
Two things are really anoying with these issues.
First: When submitting a seminar paper, a thesis, or a dissertation, you have to sign a statement saying that you followed good academic practice (OK, you might not be fully aware of what that means in every detail) and that you did all of the work on your own. The first part refers to "I did not copy-paste text from other authors without stating the sources, i.e., I did cite everything following the citation rules of my research area." And the second part refers to "I did not involve ghost writers and if someone helped me with some minor parts of the work (e.g., transcription or annotation of large amounts of empirical data or plotting fancy diagrams), I gave credit to those persons." So, someone proven guilty for not giving credit where credit is due committed perjury. This might be a legal issue and could be fined.
Second: No person accused for plagiarism and later proven guilty did show some backbone and stick to what he/she did and say something like "The accusation is probably right, I didn't know then, but I know now that I did something wrong. I appologize." They all try to make excuses and argue that it's not of interest to the public, and so on. It might be true that the paper in question is not of interest to the public, but the fact that someone made a false statement and when proven guilty tries to deny, supports the general perception of "All politicians lie." and "You can trust nobody."
The person accused to have plagiarized her Master's thesis at the ETH, argues that "I did not plagiarize, but maybe not every word in this paper has been written by me." Does that mean someone else wrote part of her thesis? In my opinion, this would violate the statement of academic integrity she most probably signed.
But the most annoying argument is: "Anyway, it's not a big deal, it was only a postgraduate (German: 'Nachdiplom') master." There is no factor of importance when it comes to plagiarism! You simply are not allowed to use other people's work without permission and without giving credit. Statements like this one support the misconception that sometimes plagiarism is acceptable.