Intimidation and harassment are the extreme ends of how the diaspora could be controlled in their behaviours in Canada, but there are more subtle and more seemingly innocuous ways to influence and govern the diaspora.
First off, many in the diaspora already know that there are certain topics and issues that you can't cross, because it will be be seen as angering Beijing or getting on the PRC's radar, and that's not even talking about dissenting behaviour. You're not talking about challenging the state. These are simply activities and social issues that are seen as sensitive by the state that you learn to steer clear of.
Another aspect is that the diaspora is encouraged to surveil each other and report on each other. There is guilt by association to begin with, so if you are associated with someone who has been seen as a troublemaker, you're less likely to get a job promotion. You're likely to be denied services. You, your work and your friends and family could be in trouble, and under that lens is where lateral surveillance comes in, in that your friends and your family could be telling on you in exchange for being able to be seen as soldiers loyal to the regime.
Some of these are self-initiated initiatives, but some of them are out of self-censorship and self-protection in the sense that if I report on someone, I would be able to steer clear of the PRC's radar.
I do want to emphasize time and time again that the diaspora is surviving the PRC's violence here in Canada in whatever ways they can. We do not assign blame onto the diaspora, but we need to address this type of behaviour, whether it is lateral surveillance or this type of social pressure and exclusion. At its core, it is the foreign principal who is pressuring the community to engage in these types of violent and ugly behaviours.