To have that conversation we'd first have to define what is meant by dissident groups. If a group is known to be hateful with potential for or threatening violence, knowing their plans is a strategy - is counterterrorism. It's akin to police doing stings for drug busts, or perhaps less controversial - for child sex trafficking; should we turn a blind eye to that and not try to infiltrate that to prevent future harm? The ideal situation is everyone feels connected to everyone else and no one willfully will harm others, that's not what happens however when there is tolerance for hate. Hate will fester under surface building its potential energy until it's released - unless it is quelled by being adequately addressed. This potential energy is what bad actors have been using to rile up the population and is threatening democracy.
We have to decide as a society what that line is - and that it isn't discussed is a problem. There's nuance required for it and a black-or-white solution - full open access for security services vs. complete blackout and being blind also isn't ideal. And is it even possible to allocate resources efficiently enough to do so, perhaps only being ready to enact resources once the hate starts boiling over noticeably? I believe the cheaper solution will be people subscribing to network(s) they trust, where it is known and accessible by the leaders and only the highest in the chain, and how their governance holds for accountability and safety will evolve over time - with best practices evolving.
For example, if all data was instantly movable from Facebook - there would have been entrepreneurs immediately developing duplicate platforms, perhaps with better UXs and features, to capture the perhaps even small amount of users who stopped trusting Facebook's controller(s) - aka Mark Zuckerberg. Even if a small amount of users initially that would have been detrimental to Facebook enough due to network effects being hurt, enough hopefully that would have kept Facebook in line, in check. For each subsequent violation of trust and without an authentic, full response or explanation by leadership, the more fodder there would be for people to disperse to more trusted networks - and people trying to bring their network with them. This mobility is more inherent to and mirrors what real life trust networks look like. If someone violates your trust too strongly and you have no interest in giving them another chance, you can (in most cases) cut them out of your network. When your data is essentially hostage however, it's like you're married, living with them, and you don't have the financial freedom or support to escape an abusive spouse.
It's interesting to see that Mastodon will grow further and allow Gab and the groups it is happy to support to continue conversing in a decentralized manner, and benefitting from tools that may or may not have the authors' blessings to be used for hate and violence.
I've never said if this is negative or positive. Overall it isn't useful to not have conversation because that allows hate to fester, for potential energy to build up enough that then once the blister is ready to pop - it can make a mess, and by mess I mean terrorism to civil war. We now know this riling up of people has been actions and funded by tyrannical governments (bad actors in control of government in other nations) who want to see democracy collapse.
The next Hitler is what we're trying to fight against, however with the internet, data, technology, the bad actors are intelligent enough to know they have to maintain some level of incognito - until perhaps one day they make a massive power move. Journalist Jamal Khashoggi¹ being cut apart alive only murdering him after, likewise the recent poisoning of Alexander Litvinenk² were brazen and obvious attacks - and becoming more and more obvious as to who is aligning to try to fail democracy and strengthen their control, and using tactics like hiring evil people and firms with no integrity like Cambridge Analytica³ who is happy to lie and/or blackmail, and promote propaganda to help bad actors win elections.
Along with current U.S. administration - Trump and family - supporting and condoning these behaviours - Jared Kushner 'justified murder of Saudi dissident journalist Khashoggi, calling him a terrorist’⁴, and Trump trying to signal to worst of humanity that there is no law and they will get away with their horrific behaviour by Trump being expected to pardon Navy SEAL Edward Gallagher of war crimes⁵. And more confirmation of Russia’s propaganda efforts by deploying its team of propagandists to cover up the murder of 298 people on flight MH17⁶ to attempt to control the narrative around the world and within their own population - something that we know China does, and Russia is copying, on a whole other level and we should be equally responsive to knowing what pitfalls exist with censorship.
¹ https://en.wikipedia.org/wiki/Jamal_Khashoggi
² https://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvine...
³ https://www.youtube.com/watch?v=mpbeOCKZFfQ
⁴ https://www.alaraby.co.uk/english/news/2019/5/30/kushner-jus...
⁵ https://www.nytimes.com/2019/05/18/us/trump-pardons-war-crim...
⁶ https://www.thedailybeast.com/mh17-russia-deployed-its-troll...