Is Tor Secure?

The Onion Router, otherwise known as Tor, is a free browser that can help you defend against traffic analysis and network surveillance which threatens personal freedom and privacy. It gives you anonymity by bouncing communication around a distributed network of relays run by volunteers all around the world. It prevents somebody watching your Internet connection from learning what sites you visit, and prevent sites that you visit from learning your physical location.

Is it bulletproof? No. There are some nodes that collect data as reported by ExtremeTech.

Reasearches have reported that 110 live nodes in Tor are “misbehaving” by collecting data on the connections that pass through it. The purpose of this collection is unclear, and there seems to be some variation in what the nodes are collecting. Some are much more sophisticated and are pulling in data that could be used to identify users. Others seem to just be tracking statistics. The most likely scenario is that some computer science researchers are running studies on Tor, which involve collecting some data. At the same time, law enforcement is running similar nodes that are trying to unmask users of illegal “hidden services” that are hosted in Tor. The Silk Road was one such hidden service.