Spies come in different flavours.
Christine Ching Kui Lee isn't the cloak and dagger type who works for China's Ministry of State Security. If she were, she wouldn't still be in the UK. Three agents who worked for the MSS, posing as journalists, were quietly deported in 2020.
The Home Secretary has already made it clear that Ms Lee's actions were "under the criminal threshold".
MI5 alleges that Ms Lee was working for the United Front Work Department, a long-established organ of the Chinese Communist Party.
Pressure and influence
According to the US government, the Department "uses a range of methods to influence overseas Chinese communities, foreign governments, and other actors to take actions or adopt positions supportive of Beijing's preferred policies".
And mostly, it does this in the open. Its website is full of photos of events. Ms Lee apparently operated in the same way, with publicly registered donations to politicians, high profile trips to Downing St, even an award (now rescinded) from Theresa May.
Concerns about her links to the Communist Party elite - she is certainly very well connected - date back at least to 2017. But she was allowed to continue her activities.
So the unprecedented warning to parliament represents a change of approach. MI5 may now have substantial evidence of her links to the Chinese Party-State. But it's also a recognition that Chinese attempts to influence the outside world come in various guises, and just because some are more public doesn't mean they are less troubling.
Pressure on overseas Chinese communities
And the interference notice also shows something else: that these public activities not only potentially harm Britain's interest but also those of Chinese people, or people of Chinese descent, living in the UK.
Last year a vice minister of the United Front Work Department said the organisation was committed to "strengthening the unity and solidarity of all Chinese people at home and abroad" as part of its mission "to build a strong and prosperous country".
Ms Lee's activities in the UK included setting up the British Chinese Project, to engage the British Chinese community in UK politics, according to Martin Thorley, a research fellow at the University of Exeter.
This was presented as a grassroots initiative. If Ms Lee is an agent of the Chinese state, it must be seen in a different light.
Atmosphere of paranoia
It's telling that the Chinese embassy in London dismissed the allegations against Ms Lee as "smearing and intimidation against the Chinese community in the UK".
The mission of the United Front Work Department is precisely to co-opt Chinese people abroad - to blur the line between the legitimate actions and interests of British-Chinese people with the political goals of the Party.
That can only damage trust, potentially creating an atmosphere of paranoia. And that is not MI5's doing, but the Chinese government's.