The tech behind the tool conceals the fact that messaging is taking place at all. It makes the communication indistinguishable from data sent to and from the app by our millions of regular users.
That is very clever.
So, by using the Guardian app, readers are effectively providing ‘cover’ and helping us to protect sources.
And of course they take the opportunity to push their app! I generally hate apps, especially for things like newspapers. This is the first reason I've seen that might make me install one.
But you're right, as aliens often are. These things are like dry herb vapes, that people use for vaping herbs, like parsley, sage, rosemary and cannabis. The idea of these things is to vapourise the chemicals in the dry plant matter, rather than burn it.
They presumably don't contain the carbon monoxide you get from burning tobacco, and the amount of tar could be lower.
They are certainly worse than ecigarette vapes, which heat a PG/VG ejuice that has had nicotine added in trace amounts, as this ejuice does not contain anything like the amount of shite found in tobacco (formaldehyde and all that crap).
I don't see the point in having these. If people need a good substitute to replace cigarettes, they should use ecigs. Not these half-way-house things which still expose them to lots of the same dangerous chemicals. But I guess this heated tobacco helps keep the tobacco producers in the market?