Revise list of default Tor Browser bridges
Six of our default Tor Browser bridges are now gone for good:
- Over at #28521, kpdyer mentioned that he's no longer able to manage his three bridges.
- Paul Pearce is also no longer able to maintain the two bridges that were set up at Berkeley.
- A bridge that was originally set up by Henry de Valence is also no longer alive.
I suggest that we remove all of these bridges. The question is: do we want replacements? Roger mentioned on IRC that we may be able to get a bunch of people to run fast bridges for us.
As for the current state of our default bridges: ln5's obfs4 bridges hover around 70% bandwidth utilisation while tvdw's obfs4 bridge sees around 100% utilisation. Interestingly, one bridge sees continuous growth in both bandwidth and users while another bridge sees a decline in users. While it seems tricky to assess the overall health of our default bridges, I think it would be a good idea to add a few new bridges.