The network layer is not the application programmers problem. I am requesting data because I want to make my application responsive. I should take into account exactly what is a "good" amount to request or what data is most likely to be requested anyways but alot of prefetching has to do with making the first load faster. So if you decide to not prefetch then many applications will force the download on the first request... Im not concerend with wifi just if the user is connected or not. If they are connected then im trying to make the resource fetching as efficient as possible which will scale from wifi and up.