If someone doesn't want to vaccinate their kids they are risking the lives of many other people in their community with this choice, not just the kids they decide not to vaccinate.
The problem is that infants can't be vaccinated for things like measles until they are 6 months old.
So people who aren't vaccinating their kids and have their kids running around spreading the measles virus in public places are risking the lives of any infants under 6 months of age who haven't even had a chance to be vaccinated.
I think there are a lot more parts of "recycling" that are working besides putting recycling products in a separate trash can.
In Chicago now, you have to pay for bags (plastic or paper) at any major store. It's 7 cents per bag. I have no numbers on how effective it has been, but everywhere I go, I rarely see anyone getting the bags from the stores.
Programs like this and NYC's styrofoam ban seem to be very effective in the "reduce/reuse" portions of reduce, reuse, recycle. Can/bottle deposits are effective too. I doubt very many cans in NYC aren't recycled.
Also, the article doesn't mention how many users sign up in a regular 24 hour period (say on Wednesday a week ago).
3M in 24h is a lot of sign ups regardless (if they had 200M users a year ago, that's over a 1% jump in total number of users), but it would be interesting to know how many more than usual that is.
I don't find it appealing to use voice as an interface. I'd much rather have a button to press.
I think the new feature in iOS where it guesses what I want to do (send a message to ABC, for example) based on previous patterns is promising. A whole screen of these actions would be great.