>On the other hand, tails tries hard to keep the user's computer free from traces. But if the secret police has already identified you enough that they go and seize your computer, then you are already in trouble.
It's that it denies them evidence. If they search all tor users, they might find proof that someone else accessed badsite.onion, but they couldn't prove that you did. Also in theory you can use tails on any computer without leaving a trace.
Imagine I want to use my work computer to browse tor, if I use their operating system then they might have spyware on it. If I use my own then I'm more secure. (They could have keyloggers or other hardware stuff, but that's more rare.)
It's that it denies them evidence. If they search all tor users, they might find proof that someone else accessed badsite.onion, but they couldn't prove that you did. Also in theory you can use tails on any computer without leaving a trace.
Imagine I want to use my work computer to browse tor, if I use their operating system then they might have spyware on it. If I use my own then I'm more secure. (They could have keyloggers or other hardware stuff, but that's more rare.)