This is quite the G20 development, a regulation (text here) has been passed in a very quiet manner that permits police to arrest persons who come within 5 metres (16 ft) of the security zone if those persons refuse to identify themselves or agree to a police search: "G20 law gives police sweeping powers to arrest people." It expires on Monday, having a one-week life span. Seems no one would have known about it but for caged arrests that have begun. Like the sound cannons, there are lots of legal surprises coming with this G20.
Cabinets do have the power to enact regulations, but this does not seem to be a run of the mill boring old regulation of the giving-effect-to-a-statute's-provisions variety. While it has appeared online, as noted by the report, it hasn't been formally published yet where notice would have been publicly and properly conveyed. It won't be published until July 3, after the summit is over. So there's arbitrariness here, this is a regulation that's basically being hauled out against an unknowing citizenry. This doesn't foster trust in the process.
Surely this request for the arrest authority to be put in place could have been handled over these many months in an open forum given its controversial nature? We've known since early December that the G20 would be in Toronto. Or, failing that, at least with sufficient formal notice having been given so it could be challenged? It was passed by the cabinet on June 2 after an "extraordinary request" by the police chief.
An arrest that has been made under the regulation also raises questions about whether it is being applied as contemplated. The Ontario ministry spokesperson quoted in the Star report says that "the law only affects those trying to enter the security zone," which is what the text of the regulation indicates too (link), that it's about entry. But student Dave Vasey who was arrested was "exploring the G20 security perimeter with a friend when they were stopped by police and asked for identification." Doesn't sound like he was trying to enter at all.
The regulation is time limited, yes, and if there were a Charter challenge of the regulation, it would occur long past the time this one will be off the books. You can see the argument here about this regulation infringing the right to be free from unreasonable search, or infringing free assembly rights and the government in turn seeking to justify the infringement due to the security risks...but for now at the summit, this regulation of highly questionable legitimacy will be applied in Toronto, without challenge.
Very bad precedent.