by old_death » 14 Dec 2012 19:01
If he was using Shareaza already on that computer it would be theoretically possible for an outside attacker (who has gained access to the machine) to use Shareaza, just as such an attacker could have used any other software already installed on the system.
There are three other points however that seem much more likely to me:
1. Your client installed Shareaza and his children did find the program and use it illegally without knowledge of your client (maybe without even knowing that they were doing anything illegal at all).
2. Your client has set up remote control for Shareaza and somebody else has gained the password.
3. Your client downloaded files without knowing himself that the download itself was illegal. You should know that files illegal under the copyright law of one or multiple countries don't have file names like "Music by bandXY - the download of this file is illegal in country1, country2 and country3.mp3". So there are cases where it is simply not possible to tell whether a download is a legal one or not – and by this I mean that without downloading the file in question, even a lawyer or somebody trained in copyright laws etc. might be unable to tell the difference between a legal an an illegal download.
Also, there have been cases where lawyer offices did host (distribute) illegal files themselves under a false name to lure people into downloading these files so that they could sue the poeple afterwards (In German, there is even a specialized word for such law bureaus who make their money by suing people following such copyright infringements: "Abmahnkanzlei"). The big problem in such cases is that the person downloading the file by name often doesn't even realize he/she has downloaded something illegal until the download has been finished completely and he/she has reviewed the file. In extreme cases, between both events he/she could have uploaded the file multiple times and be guilty of multiple copyright infringements.
As this is kind of an official discussion here, I'd like to point out that all of what I wrote (and what I might write later within this or other topics on the subject) represents a personal opinion and is not the opinion of the Shareaze Support/Development team. I also cannot guarantee for the completeness or correctness of what I wrote. (You might note that after past dealings with lawyers, we tend to get a bit paranoid whenever you guys pop up...)