If Twitter had shut down yesterday too, it'd be impossible to tell what kind of impact Wikipedia's anti-SOPA protest would have had on the tweeting masses. But thankfully it wasn't, which means that we know today that Wikipedia's semiofficial shutdown hashtag, #wikipediablackout, had quite a late-night boom a few hours after the site dark. At 4 a.m. on Wednesday nearly 1 percent of all tweets worldwide (to be precise, 0.93 percent) were tagged #wikipediablackout. Graphed below is Twitter activity for the hashtag according to Trendistic.

Not a bad sign of the protest succes, at least at getting the (tweeted) word out about the anti-piracy bill. For comparison, tweets containing "Bieber" -- as in Twitter's always-trending first love, Justin Bieber -- hovered around 0.1 percent on Wednesday.

We say #wikipediablack is "semiofficial" because its success was promoted by Wikipedia itself and according to The New York Times Wikipedia's San Francesco office had a wall projector projecting every tweet tagged with it. ("It went from very little movement to moving way faster than you could possibly read it," says one Wikipedian.) But " #wikipediablack" is just one measure. Stepping further back, we see that the online protest had an even wider impact when we also include tweets with just the phrases "Wikipedia" or "SOPA." Tweets with the latter phrase alone constituted 3.5 percent of all tweets at 1 p.m. yesterday.