It's not a slippery slope fallacy, if the slope is actually slippery.

Bad actors are everywhere and are especially drawn to positions of power (normal people see life-changing power over others as a major responsability, hence a burden).

This is why you limit power concentration on any single individual or organisation, have checks-and-balances on power and have higher demands of transparency and reporting one those with power than on run-of-the-mill citizens.

Of course the assholes drawn to power will do everything they can to subvert, nullify, remove or bypass those mechanisms and the reasons why we see right here in how these people (never forget, organisations are not sentient: it's always people making decisions) because they could choose to use these kind of laws that break the spirit of the Rule Of Law in democracies - which we were told were for use against terrorists (a very specific type of mass murder) - against demonstrators who have not even committed an actual crime and whose history indicated that the biggest crime the would ever commit would be mild property damage, something nowhere near the range of actual murder, much less mass murder.

In Canada I'm very wary of the current trial against the leaders of the Freedom Convoy for this reason. Popular sentiment at the time of their protest was that they were bad for blocking the road, and what comes from this trial could set precedent that could be used to criminalize climate and social justice protests in the future.