I believe in most countries only a court can decide if a site is illegal or not. Not you. And as far as I know this is true in both France [0] and Germany[1].
IANAL.
[0] I got the impression it was a French site
[1] just guessing where you live
IANAL.
[0] I got the impression it was a French site
[1] just guessing where you live
No.
Longer version: it's illegal only if a license is required, which is a matter of the copyright law of the jurisdiction relevant to the act. In the US, that question may turn on things like fair use analysis, which can be tricky.
Could you clarify why you think that this site does not require a valid license to re-host and re-compile papers?
Time-shifting is one of many examples of where copying a whole work was found to be fair use; the idea that fair use applies only to citations is very, very wrong.
Fair use is extremely precedent dependent (and very hard to predict without clear applicable precedent) because the statute law gives only factors to weigh in the analysis.
> Could you clarify why you think that this site does not require a valid license to re-host and re-compile papers?
I didn't state an opinion on that; I said that, because it skips the question of whether license is required, the blanket statement that rehosting without a valid license is “clearly illegal” is inaccurate and overbroad.