An increasing number of popular websites will go “black” tomorrow, in protest of the “Stop Online Piracy Act” (SOPA) and the PROTECT IP Act (PIPA), the sibling anti-piracy bills currently in Congress. But Twitter will not be one of them.

In response to questions about whether Twitter would join the likes of Reddit and Wikipedia in the January 18 blackout, Twitter co-founder Dick Costolo tweeted that it would be “foolish” and “silly” to shutdown a “global business in response to single-issue national politics.” Many took this to mean that Costolo believed any site that goes black (or, more likely, shows an anti-SOPA/PIPA landing page in place of normal content) over a single bill is “foolish” and “silly.” He later clarified that these adjectives only apply to Twitter going black, not any other organization.

Of course, anti-SOPA/PIPA activists want to have as many companies on board with the blackout as possible. There has been a concerted effort to get Google and Facebook to join in the protest party, but so far, they haven’t taken the bait. (Even though both companies have come out strongly against the legislation.) The more sites, the bigger the message, or so the theory goes.

Thing is, Costolo’s right; it would be foolish, silly, and counterproductive to the anti-SOPA/PIPA movement for Twitter to go offline. When Wikipedia and other sites are down tomorrow, the activists (and, more importantly, news organizations) are going to need a place to go to gauge the effects of the blackout. And no other service is better for taking he pulse of the here-and-now than Twitter.

The activists in this movement, both individuals and companies, need a way to communicate with each other, and with the people who are suddenly met with a splash page on Wikipedia asking them to call their senators. Not all of these people are going to be happy about not being able to get what they want — which is, incidentally, the point of the blackout: to show the possible censorship effects if SOPA or PIPA became law — and not all are going to be sympathetic to the cause, or even grasp what the hell is going on. Luckily, Twitter will be there as resource for explaining the confusion.

Besides its usefulness to the anti-SOPA/PIPA crowd, Twitter is also used by millions of people around the globe, many of whom most certainly do not care about, and are completely unaffected by, US domestic policy. For those users, shutting down Twitter would be an injustice, not to mention highly annoying. It is for this reason that Wikipedia has limited its 24-hour blackout to English-language pages only. Still, oblivious foreigners will be affected, but the negatives are at least being limited.

Even with Twitter there to help smooth the rough edges of tomorrow’s unprecedented online activism, there’s no guaranteeing the effects of the protest will be in the favor of the activists. Public opinion has a way of doing its own thing, especially when it’s guided by untested techniques like shutting down websites.

So, will the Jan. 18 blackout be a success? Who knows. But you can be sure we’ll be checking Twitter all day to find out.