Most "end points", unlikely..

Anyone can run its own proxy and provide it as a public service, if you have bandwidth that you do not need you can consider it, as an advantage, your traffic will be mixed with the traffic of many other users, which is considered a smart move. Snowden, in his book "Permanent Record" explain the reason of this cyber security practice.

Now, governments spy agencies and law enforcement on a case basis may create farms as exit nodes to collect and analyze traffic, not an easy task and very expensive.