This kind of spying seems necessary and appropriate to me, provided it is done under the appropriate legal framework. The security concern with Russia and Belarus are self evident now, and the security concerns around hosting a large dissident population must be enormous. You don't want extremists within the dissident movements (it'd bad if the Putin assassination was planned on your soil), nor penetration of the dissident movement by foreign intelligence (it'd be a bad if the opposition leader got novichoked on your soil). I'm not sure how else to address these kinds of problems in society except with some kind of well regulated security apparatus (making the big assumption that it is well regulated here).