Yesterday Aaron Swartz, a close friend and collaborator of ours, committed suicide. This is a tragic end to a brief and extraordinary life.

Aaron did more than almost anyone to make the Internet a thriving ecosystem for open knowledge, and to keep it that way. His contributions were numerous, and some of them were indispensable. When we asked him in late 2010 for help in stopping COICA, the predecessor to the SOPA and PIPA Internet blacklist bills, he founded an organization called Demand Progress, which mobilized over a million online activists and proved to be an invaluable ally in winning that campaign.

Aaron's eloquent brilliance was mixed with a complicated introversion. He communicated on his own schedule and needed a lot of space to himself, which frustrated some of his collaborators. He was fascinated by the social world around him, but often found it torturous to deal with.

For a long time, Aaron was more comfortable reading books than talking to humans (he once told me something like, "even talking to very smart people is hard, but if I just sit down and read their books, I get their most considered and insightful thoughts condensed in a beautiful and efficient form. I can learn from books faster than I can from talking to the authors."). His passion for the written word, for open knowledge, and his flair for self-promotion, sometimes produced spectacular results, even before the events that proved to be his undoing.

In 2011, Aaron used the MIT campus network to download millions of journal articles from the JSTOR database, allegedly changing his laptop's IP and MAC addresses when necessary to get around blocks put in place by JSTOR and MIT and sneaking into a closet to get a faster connection to the MIT network. For this purported crime, Aaron was facing criminal charges with penalties up to thirty-five years in prison, most seriously for "unauthorized access" to computers under the Computer Fraud and Abuse Act.