https://www.theregister.co.uk/2017/08/21/gchq_knew_marcus_hutchins_risked_arrest_fbi/

Secretive electronic spy agency GCHQ was aware that accused malware author Marcus Hutchins, aka MalwareTechBlog, was due to be arrested by US authorities when he travelled to United States for the DEF CON hacker conference, according to reports.

The Sunday Times – the newspaper where the Brit government of the day usually floats potentially contentious ideas – reported that GCHQ was aware that Hutchins was under surveillance by the American FBI before he set off to Las Vegas.