Not in 20202020*. In 2016.
The "3,300" figure is likely a reference to a 2017 piece in The Times.
More than 3,300 people were detained and questioned last year over so-called trolling on social media and other online forums, a rise of nearly 50 per cent in two years, according to figures obtained by The Times.
*Original question: "Were over 3000 persons arrested in Britain for social media posts in 2020?"