Mark Wilson writes: There are many problems with the censoring of online content, not least that it can limit free speech. But there is also the question of transparency. By the very nature of censorship, unless you have been kept in the loop you would simply not know that anything had been censored. This is something the Electronic Frontier Foundation wants to change, and today the digital rights organization launches Onlinecensorship.org to blow the lid off online censorship. The site, run by EFF and Visualizing Impact, aims to reveal the content that is censored on Facebook, Google+, Twitter, Instagram, Flickr, and YouTube — not just the 'what' but the 'why'. If you find yourself the subject of censorship, the site also explains how to lodge an appeal.