When you use Tor your Internet traffic is routed via Tor which goes through several random relays before exiting the Tor network. Tor is "designed" so that it is theoretically impossible to know the original computer that the information came from assuming you are using Tor the right way. Exit node can see your plaintext traffic assuming you aren't using HTTPS. Theres an article in 2007 some researchers intercepted emails and passwords from hundreds of users just by running a simple Exit Node. As long as you use HTTPS you should be fine. Tor does not leak your identify, it is the users who dont use tor correctly who are responsible for the leakage. Here's a list of some common mistakes tor users make that could reveal information about the original user up to leaking the actual ip address.
- Changing proxy settings
- Installing browser add-ons
- Installing/Using plugins such as Flash
- Some recommend to disable Javascript altogether
*- Example: Vulnerability uncovered in Windows firefox & chrome "new ip
check" option allows sites to determine users actual IP even when
using VPN, because Javascript code within visitors browser can
executed behind the scenes without users ever knowing see Reddit Post.
- Always keep browser updated - Vulnerabilities - Leak information
Example: Browser vulnerability may reveal users real IP Address
Site: Real IP Leak - Browser Vulnerability
Site: 0day Javascript Firefox Flaw
- Even simply watching a video, video player the browser
may be using may leak your information
- Avoid DNS Leaks
When your browser is not setup correctly and queries DNS
directly instead via VPN/Tor all your anonymity is lost.
How DNS Leaks Can Destroy Anonymity
There are many many more possibilities but under proper usage, using the tor bundle, up-to-date, w/o javascript, forcing https, disabling all add-ons and plugins, although still not full-proof (maybe the Russians have 0-day exploit?) but will GREATLY reduce your chance of exposing your identity.
Best of luck,
eof0100