The Sarah Wilkinson post is a good one to point out, in fairness, as it shows how proscribing 'terror organisations' can quickly spiral into madness.
On the one hand, ISIS (let's say) are without question a terror organisation and I'd support the monitoring of anyone who seemed to show support, active or passive, for their cause.
On the other hand, while Hamas are also a terror organisation, it's quite telling that they would arrest random people for comments and statements instead of monitoring them. It shows that the state doesn't believe these people are the same level of threat as, say, the guy who accesses bomb-making material associated with ISIS or the Taliban or whatever.
If they're not arresting people who in someway support ISIS or the Taliban immediately, why not? And why is it that terrorists are "known to the authorities" after they committed a crime? If they're known, does that mean they've been arrested, questioned, and had their devices searched already? Because a lot of the time, it doesn't feel like it.
This is concerning double standard scare tactics, and I 100 % agree that it's wrong to treat people differently. The intent seems clear to me: they will scare people they don't think are a real threat, but secretly surveil others. That's bollocks.