Over the past few days, John Key has been talking up the "threat" of kiwis fighting in Syria, and the need for new laws to stop them leaving or returning to New Zealand. On the latter point, there's an obvious freedom of movement issue: every person has the right to leave here, and every kiwi has the right to return. Cancelling of seizing passports and stranding people overseas violates that right unjustifiably. And if done without judicial process, it constitutes an extra-judicial punishment of exile - the sort of thing we criticise foreign regimes for doing.
What about punishing that tiny number of jihadis for fighting overseas? The way Key talks, you'd think that it wasn't a crime. But he's lying. The groups he is concerned about - IS and Al-Nuisrah - are both designated terrorist entities [see p. 149 - 150]. Which means that anyone recruiting for them, financing them, or participating in them is committing a crime punishable by up to 14 years imprisonment. New Zealand claims extraterritorial jurisdiction over its citizens for those crimes, so there's no doubt they can be prosecuted. In short: we don't need new laws to fight terrorism. All we need is for the police to do their jobs properly to enforce the old ones. And if they can't be arsed or don't want to do that before punishing people, then I think we have a much bigger and more immediate problem with them than with people leaving NZ to fight overseas.