Via the Electronic Frontier Foundation:
Twitter’s increasing need to remove content comes as a byproduct of its growth into new countries, with different laws that they must follow or risk that their local employees will be arrested or held in contempt, or similar sanctions. By opening offices and moving employees into other countries, Twitter increases the risks to its commitment to freedom of expression. Like all companies (and all people) Twitter is bound by the laws of the countries in which it operates, which results both in more laws to comply with and also laws that inevitably contradict one another. Twitter could have reduced its need to be the instrument of government censorship by keeping its assets and personnel within the borders of the United States, where legal protections exist like CDA 230 and the DMCA safe harbors (which do require takedowns but also give a path, albeit a lousy one, for republication).
Twitter is trying to mitigate these problems by only taking down access to content for people coming from IP addresses the country seeking to censor that content. That’s good. For now, the overall effect is less censorship rather than more censorship, since they used to take things down for all users. But people have voiced concerns that “if you build it, they will come,”—if you build a tool for state-by-state censorship, states will start to use it. We should remain vigilant against this outcome.