I see from the Tor network-metrics page that there are only ~1000 exit relays. Even if the Tor browser is secure, having so few exit relays limits the anonymity provided, right? How could the Tor Project facilitate and encourage new exit relays?
Having only a thousand exit relays does not harm your anonymity directly.
If there were only a thousand users, then that would be a problem. But there aren't. There are many thousands of users, and you get your anonymity from blending in with them. Or, in other words, you derive anonymity because nobody can tell you from the hundreds of thousands of other Tor users.
However, having few fast exit relays harms diversity. Concentrating a large portion of the network isn't good because then a single node can see a significant part of the entire traffic.
Yes, there are only 1k exits.
It is easy to explain why so. Earlier, Internet was a paradise of spammers. There are couple of generations of spammers growth in the network.
Once you've setup your node as an exit, you've lost your IP address forever.
Just try it yourself.
You will become blacklisted by every kind of SpamCops. Requests from your IP would be locked on Google, Yahoo, etc...
Even wikipedia will deny you to share your knowledge.
But it is not so bad. The real terrible thing is a 2.5k of middle-relays only.
Peoples share thousands of terabytes of pirate's DVD, but wantn't share their bandwidth. The main problem that I see, they just don't know the difference between the middle-node and an exit. Who tries once setup an exit, now staying away from Tor. The simplicity of keeping middle-relay must be illuminated another, more popular, way.
- There is no incentive from doing so.
- In other systems not related to Tor, usually the users are happy to contribute back to whatever they are using. This doesn't work for Tor. Most users interested in Tor want to hide their identity. Anonymously hosting a relay is difficult. They fear, that hosting even a middle relay will give them unwanted attention.