@Sean433I'm not saying that I disagree with the logic behind it, necessarily, what I'm saying is that I don't think it'll hold up - the Ontario Human Rights Code specifically protects against discrimination based on age in accommodation.
http://www.ohrc.on.ca/en/ontario-human-rights-code
Whether it's a given that it's specifically ltr "housing" versus str accommodation is unclear. I do expect that this will be challenged, and it will be overturned.
What I'm also saying is that Airbnb COULD, instead of creating policies that dangerously skirt the law, back its hosts and enforce their rules...or do a host of other things as @Sarah977 has mentioned upthread, so that people who are looking to party wouldn't immediately think that renting someone else's property via Airbnb is the way to go. Allowing exceptions to a law against discrimination is a very slippery slope indeed, and I'm not sure that this is the only or best way to accomplish protecting hosts and neighbourhoods.
If the penalties for behaving badly in any case were enforced and applied, Airbnb properties would not have the reputation as a great way to have a party in the first place. Collection up front of a security deposit is a big deterrent, and one that has been in use and has been working for many other rental business models (hotels, car rentals, even other OTR sites from what I understand).
My other issue with this policy is the location piece. I live in a college and university town. 2/3rd of the people living here that are under 25 are "from" elsewhere, and likely their profiles list their hometowns. They live here now, however, and they have friends to party with here. How does this policy protect against that? No doubt Toronto is similar.
I think that instead of constantly trying to reinvent the wheel, a step back to correct the basic flaws in the administration of the business is what Airbnb should be doing.
I thought that the neighbourhood hotline was already part of the "10-day sprint" announcements, arising out of the Orinda murders. I guess Airbnb is stepping up the rollout of it for Toronto. Like you, I have concerns that it may be used by disgruntled neighbours. We shall have to see how it works and whether it is useful (not that we'll likely ever be given any meaningful feedback on it).