As a massive site based on short bursts of unfiltered commentary, Twitter has become a major test case for the limits of speech on the internet. As we've seen today, that can mean offending community norms with things like pornography; more frequently, it's the result of conflicting ideas about what is legally acceptable. The New Yorker has taken a look at one of the most recent legal scuffles: a French court that's demanding Twitter help identify authors of anti-Semitic tweets that could violate the country's hate speech laws. "Twitter finds itself with the ball, trying to dribble through diverging laws around the world," writes Emily Greenhouse, "to hold onto its philosophical ideals — total, protected freedom of expression — as it holds onto its users and advertisers."