[dspillett]

The streaming sticks the article is discussing basically need network access to function. They might support streaming from local media sources and file shares too, but that is also done over WiFi. Unless you have a properly firewall controlled home (very few people do, I'm pretty nerdy and most devices on my network can just NAT to the outside these days) then just giving it a WiFi connection gives it access to the wider network from your location.

You'll probably find the projectors are pretty much the same hardware and OS as the sticks except with the projection device added where the stick just has an HDMI output. It might have HDMI-in too so it can just be used as a screen for another device, but there are definitely some units out there that are network-play-only.

You aren't wrong about giving cheap crap like this access to your network (and via that the public network) is risky, but that convenience you (and I) would say no to is exactly what they are bought for.