I have been surprised at the extent of criticism of Twitter and Facebook for closing US President Donald Trump’s accounts with them (“ Trump Twitter ban reminds of Big Tech’s censorship powers ”, January 13). There must be some limits to free speech, as was established in the Schenck v United States case in 1919. US Supreme Court Justice Oliver Wendell Holmes cited “falsely shouting fire in a theatre and causing a panic” as an example of speech that should not be protected. This principle surely applies even to a country’s president. The view that Trump should nonetheless be allowed to say what he likes has been supported by, among others, The Sunday Times . Social media platforms are under fire for a number of important reasons right now, though it does not seem to have stopped billions of people from continuing to use them. One of those reasons is that they should take some responsibility for what is posted on their sites. This is what they have just done. Andrew Kinloch, Mid-Levels Trump tripped up by web of own lies It is difficult to see how Donald Trump can escape from the lies he has entangled himself in. With his other great lie, that Barack Obama was born outside the United States, there was at least a document that could disprove him and he changed his position . Given that dozens of lawsuits filed by his supporters have been rejected by the courts, it is difficult to see what additional evidence could cause him to change his mind on the election. Perhaps the best that might be expected of him would be to go silent on his claim and say that people should respect the courts. If there is any further violence he should denounce it in no uncertain terms. No more “ We love you. You’re very special ”, as he said on January 6, or “ very fine people on both sides ”, as he said after the Charlottesville protests in August 2017. Bruce Couchman, Ottawa, Canada