It varies from state to state, but at least here in NC voting history is available to the world. You can jump on the SBOE website right now and see every election I voted in, for example, since 1992. What I'm not sure about, is how much latency there is in terms of when the public record is updated.

And before anybody asks, no they don't report who you voted for. Just the fact that you voted, whether the election was a general election or primary, and if it was a primary, which party's primary you voted in.

Available to anyone actually in most states I’m aware of.