Tor and Tails don't protect you by making you look like any random Internet user, but by making all Tor and Tails users look the same. It becomes impossible to know who is who among them.
Your Internet service provider (ISP) and local network can see that you connect to the Tor network. They still cannot know what sites you visit.To hide that you connect to Tor, you can use a [[Tor bridge|doc/anonymous_internet/tor]].
The sites that you visit can know that you are using Tor, because the <a href="https://metrics.torproject.org/exonerator.html">list of exit nodes of the Tor network</a> is public.
Parental controls, Internet service providers, and countries with heavy censorship can identify and block connections to the Tor network that don't use Tor bridges.
[[!img doc/anonymous_internet/tor/tor.svg size="600x" link="no" alt="A Tor connection goes through 3 relays with the last one establishing the actual connection to the final destination"]]
Observe your traffic. That is why <i>Tor Browser</i> and Tails include tools to encrypt the connection between the exit node and the destination server, whenever possible.
Pretend to be the destination server, a technique known as <i>machine-in-the-middle</i> attack (MitM). That is why you should pay even more attention to the security warnings in <i>Tor Browser</i>. If you get such a warning, use the [[New Identity|doc/anonymous_internet/Tor_Browser#new-identity]] feature of <i>Tor Browser</i> to change exit node.
A powerful adversary, who could analyze the timing and shape of the traffic entering and exiting the Tor network, might be able to deanonymize Tor users.These attacks are called <i>end-to-end correlation</i> attacks, because the attacker has to observe both ends of a Tor circuit at the same time.
No anonymity network used for rapid connections, like browsing the web or instant messaging, can protect 100% from end-to-end correlation attacks. In this case, VPNs (Virtual Private Networks) are less secure than Tor, because they do not use 3 independent relays.
End-to-end correlation attacks have been studied in research papers, but we don't know of any actual use to deanonymize Tor users. For an example, see <a href="https://www.freehaven.net/anonbib/cache/murdoch-pet2007.pdf">Murdoch and Zieliński: Sampled Traffic Analysis by Internet-Exchange-Level Adversaries</a>.