I'd definitely ask them, in as non-guilt-inducing a way as possible.
I'm 26, and I'd probably politely accept them, try one or two recipes, put them on my bookshelf, and never touch them again, but never feel like I could get rid of them for at least five years. If one was particularly good, I'd maybe type it into a Google Docs document for quick reference later.
And I cook every meal from scratch. Cookbooks just don't fit my lifestyle. Everything's electronic.
The annoying thing about internet recipes is wading through six pages of the poster's life story and thirty artistically rendered pictures before you can get to the damned recipe. Even with that annoyance, the majority of the recipes I make are now looked up online.
This is definitely an issue, and much worse if looking up a recipe on a smartphone (yeah, GuitarStv, I know :P ). To that end if I find a recipe we end up making a lot, it will get "archived" into a friendly Google Doc that doesn't take five years of scrolling to see how many green onions we need to have on hand this week.