The license is what gives you legal permission to make copies in the process of installation; copying is otherwise an exclusive right of the copyright owner. So that’s very much an “if you win the argument on rejecting the license, you still lose” situation.
In France and Germany, you are allowed to copy copyrighted works, as long as it's for private use (including family and "private circles") and you don't sell it. https://fr.wikipedia.org/wiki/Copie_priv%C3%A9e#Principes_g%...
For example, before fast internet connections, people would borrow music CDs from libraries and copy them.
In some countries, such acquisition of a copy is legal on its own.
Traffic inspection by ISPs (let alone sharing of collected data with third-party entities) in the EU is required to have a legal/technical basis and/or user consent, depending on what is being done and for what purpose [1]. Even attempts at blanket (meta)data retention for law enforcement agencies have pretty much been ruled illegal in the EU [2] and Germany [3].
What probably happened is your friends were torrenting, and some entity acting on behalf of copyright holders got their IP from public trackers/DHT. Then they came knocking to the ISP with a cour order, asking for information about the person behind that IP address, and the ISP gave them that [4]. Finally, the entity sent a C&D to your friends.
[1] - See the EU DPS' opinion on how the existing EU legal framework affets ISPs' data inspection abilities: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELE...
[2] - See Directive 2006/24/EC, tl;dr https://en.wikipedia.org/wiki/Data_retention#European_Union
[3] - htps://www.bundesnetzagentur.de/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Anbieterpflichten/OeffentlicheSicherheit/Umsetzung110TKG/VDS_113aTKG/VDS.html
[4] - https://blog.raychenon.com/file-sharing-violations-in-german...
I mean you can, we can do "anything" but there are repercussions for each action.
It’s literally just using the P2P nature of bittorrent to get peers’ IP addresses (you can do that too! Just start any torrent and look at the peers tab in your client), then using the legal tools to request data about a person breaking the law using such and such IP address.
If you extend this to everything you can have massive surveillance without cookies, MAC address of device, IP address for each package and you know who is accessing what kind of content on internet. So, why wait whenever someone reads article about class 1 drug just brake his door and arrest him, isn't it ?! I mean fork privacy, democracy, and judicial process, just lets immediately arrest everyone :/
Anyway, in German scenario how can you certify that someone was not hijacking your router?
(As per friends case, they had friend who was sleeping over and connected to their Wifi ...)
Some lawyers are even using sites similar to https://iknowwhatyoudownload.com/
It probably costs less to pay the amount than fighting it in court. I think it's capped at 450 Euro or something? But I know some people who got scot free by merely having a lawyer send a response.
Art. 23. Copyright
The scope of the work's own personal use
1.
Without the author's permission, you may use an already disseminated work for your own personal use free of charge. This provision does not authorize to build on the basis of someone else's architectural and urban planning work and to use electronic databases that meet the features of the work, unless it concerns own scientific use not related to profit-making purposes.
2.
The scope of personal use includes the use of single copies of works by the circle of persons remaining in a personal relationship, in particular kinship, affinity or social relationship.
but software is explicitly excluded by 77:
https://en.wikisource.org/wiki/Polish_Copyright_Law#Chapter_...
Art. 77.[32]
Provisions of Article 16 subparagraphs 3-5, Articles 20, 23, 231, 27, 28, 30, 331-335, 49, paragraph 2, Articles 56, 60 and 62 shall not apply to computer programs.
That is a big part of why companies try to claim they never sold you a copy in the first place, only licensed it.
In other words, if I click "send" on my resignation email to my employer, but later argue in court that I totally didn't mean to actually resign, but only to check if my email program works, I may have a challenging case.