Yes but the nodes are not connected to you as a tor user except by the ip address of the other node you came from, and the nodes change frequently.
For tor to be useless there would have to be some mechanism for lea to become the entry node consistently, but tor randomizes that just because of the danger of it.
The biggest flaw is that tor doesnt support encrypted traffic and thus the exit nodes can steal passwords and data, but the exit nodes have no access to your ip.
You do have to be careful not to transmit any INFORMATION over tor that can be connected to you by other means, your name, address, or identifying information. And have all scripting stuff turned off, java, etc
