I have a 3G Mobile Wireless Modem/Router (TP-Link M5250[1], heavily recommended btw) and this "if wireless connection present, download all the things" attitude really annoys me. Android is a big offender. Why on earth I don't get a "download updates automatically only on this particular network" setting... Whatsapp, Google Maps and many other apps too make the same false assumption.

[1]: http://www.tp-link.com/en/products/details/cat-4692_M5250.ht...