General guidance policy and numerous court cases. Not all footage is 24 hours, most is however. Some exceptions go for 48 hours. [http://timetravel.mementoweb.org/list/2010/http://www.polize...]
Video surveillance, especially when in public spaces, is frowned upon and there is a long rat tail of court cases.
The law is very strict in when, what, who and how long video surveillance is allowed, including the 24 hour limits, though in case a crime is suspected the footage can be kept for 14 days until a crime is confirmed. [https://recht.nrw.de/lmi/owa/br_bes_text?anw_nr=2&gld_nr=2&u...]
>we both know the truth is that (some) EU cops simply get away with it.
Generally, they are reprimanded or even punished when such behaviour is discovered as it is a violation of various laws, including privacy.
>How else will you sue the police if it wasn't reasonable at all ? How will abuses be discovered ?
Generally, any evidence the police brings up in a court case requires that the police has an explanation on how they got to that evidence. That may have been illegal, in which case a second case might be brought up and the involved officers will be punished.
However, unless the evidence they collected is wrong due to the surveillance (the bar is very low on the police being guilty of forcing you to commit a crime), the evidence will be used regardless (a few edgecases but generally evidence is not poisoned if gained by wrong means like in the US IIRC).
>I doubt it's the only one. Call me when they change the law back so they can't legally do this
Already is, which is in part why the BND stopped this too.
The bar is high for someone tapping the phone or otherwise doing remote communication surveillance, [GzBBPF, Section 1, 2, 4 and 7]. Unless there is a very strong suspicious that you commited treason or commited a federal crime and there is absolutely no other way to prove you did it, they can't legally tap the phone.
Basic dependencies of your argument: the police force will never abuse surveillance, then not make a court case out of it.
Second basic dependency of your argument: the court will easily rule against the very forces they depend on if they find violations.
These are reports German police officers that got caught, shall we say, being VERY untrustworthy:
So I feel like I've provided plenty of evidence that the police cannot be trusted to act correctly, or even just sane. The German police, clearly, is no exception to this rule. Therefore Germany trusting them to do the right thing is just hiding abuse, not preventing it.
You also left the question unanswered: if tapping is so correctly and justly done, then why does it need to be such a big secret ? There is a case to be made that, sometimes, it needs to be kept secret DURING an investigation, but why afterwards ? In many cases, even that is not necessary, when for instance following or tracing someone who was brought in to the police station, it seems to me like there is no reason whatsoever to keep it a secret that the police reads his mail/call logs/... Why do they want this perpetual secrecy, if not to hide abuse ?
The answer is very simple: because Germany hires neonazis, cannibals, violent bullies and worse into their police force, and police officers like those are also trusted with tapping people's conversations.