I scan a QR code at my local coffee shop almost every (week) day. I use an app that acts like an electronic loyalty card - you scan a QR code when you get a coffee, and every 10th coffee is free (and I find I'm actually more likely to do it, unlike with cardboard loyalty cards where it feels like you're inconveniencing someone when they're busy by making them mark it).
I'm pretty sure there's something similar mentioned in one of the Red Dwarf novels (with the experience ending in the use of genetically engineered players).
It may well be that, but that doesn't make it okay. They shouldn't be building an email database by scraping, which is almost certainly what happened.
In a vaguely related note: I recently had a situation with an organisation that kept bulk emailing a plug for its conference and would ignore requests to eliminate all addresses using[mydomain].com from their database (they were sending email to aliases as well as actual mailboxes).
Interesting link. What would be nice would be some kind of comparison of different offerings (e.g. the online Codeacademy-style stuff) by either an experienced developer or a novice to see how they stack up against each other in terms of usefulness.
I enjoyed it a lot. Sure it's not a AAA title - but it's good, mindless fun. Especially given its extremely appealing price point. (And, yes, I haven't finished it.)