Serial Upvoting Incident

Question

I had my first incident of serial upvoting (and of its reversal). Yesterday (my time), some good Samaritan, or strong supporter (or tester of the SE system, for that matter), upvoted in a single minute six of my answers:

Deriving and explaining the weighted cost of capital

What causes the "imperialism of economics" and how did it start?

Comparative dynamics in forward-looking equation

Do large public companies ever "quit while they're ahead"?

Have there been any true "communist" nations as Marx envisioned?

The $\sqrt{N}$ convergence of semiparametric estimators of Newey 94, why does it converges to a normal distribution?

And the SE system functioned as promised: come end of the day, it reversed all of them.

Just in case this was a well-meaning "scheme" by some comrade here to increase reputation levels for the benefit of the site, take heed: you are being watched.