I'm old enough to remember when a white South African runner, Zola Budd, came to the UK and competed for Great Britain as a way round the sporting boycott of apartheid South Africa. Budd, who was 18 at the time, had to put up with anti-apartheid activists protesting at every meeting she raced at.
There was an argument that, at 18, Budd was too young to be targeted by political activists. But my view was - and is - that she was old enough to engage in a deeply political act, namely breaking the sporting boycott. And, of course, she was old enough to vote - as is Thunberg.