is more about putin's weariness over coronavirus. just to give you another example, back in december he held his marathon annual press conference, and anyjournalist who wanted to attend the event had to pass three pcr tests and, once they got to the venue, they had to go through a kind of disinfection tunnel which sprayed them with sanitiser. and when they eventually got into the hall they were a good 20 metres away from the russian president anyway. 0k, more from you, francis, in a moment. we'll bare that in mind. but going on, what's going on near the ukrainian border is also the subject of much analysis by open—source investigators. these are the online sleuths, often amateur, who are trauling through social media posts and satellite imagery to track the military hardware that's on the move in the region. such investigative techniques have now been co—opted by mainstream news outlets. and we're going to hear about the huge impact some of them have achieved in the last few months. we've got some of the best in the business with us, including alison killing who won a pulitzer prize for her work last year. alison used satellite imagery