How many U.S. Internet users could Wikipedia’s Wednesday protest likely affect? Up to about 10 million, says online research firm comScore Inc. Internet users won’t be able to search the English version of the free encyclopedia this Wednesday, with the site planning an unprecedented 24-hour blackout to protest controversial online piracy legislation. Wikipedia says it is working in concert with other websites, including social news site Reddit, which said Tuesday that it was joining the protest. Click here for more on the story.