* as a provocation for -> as a catalyst for ? (sorry sj1990 I have a weird commonly confused mind
)
If you're pursuing the technology thing you could explore its impact on the type of socialisation experiences youth undertake over time/genderwise/generationally etc ?
In itself the dependence of teens on the internet is definitely too broad - what is your cross cultural component? Dependence on internet relative to what? You suggested relative to books so you would be exploring different forms of media and their impact on youth but even then it doesn't seem completely appropriate to my pedantic mind because were teens ever addicted to books? Like what aspect of the internet/books are you interested in? Their purpose for entertainment? For information? For communication/socialising agent with peers? A combination of these aspects?
When you say effects of mobile phones on society that's probably also way too broad - select a smaller group/subculture to investigate (society is GIGANTIC lol), consider what is the aim of your investigation? If you prefer you can start with a really broad area like the ones you suggested and then when you research you may find specific areas more interesting.
What's most important is to choose a topic related to the world we live in that can keep you absolutely fascinated all year (or closest to), because I don't think I'm the only one whose been in tears over it numerous times (that probably won't be you lol but it makes it easier to not feel like giving up)
Is there any cultural phenomenon you're interested in? As in, is there anything interesting about your own culture or any culture that you've ever been really curious about? That's more likely to get attention then a more generic topic but then again it depends how you do it. Good luck!