Week 9 and 10-A person known to you who most threatens the notion of native/immigrant in digital culture.

I Think my Granddad threatens the notions of digital immigrants and natives, He has just recently turned 70 and therefore should most definitely be under the digital immigrants category according to the general concepts established by Prensky.
He works as a graphic designer and has done ever since I can remember, he used to work for a company but is now self employed and does many different types of design jobs, such as photo editing, magazine and book lay outs. He knows how to use both PC's and Mac's and owns both, he uses photoshop and knows how to use it better than anyone I know who falls under the typical digital native, i.e anyone from my generation. His accent is much more digital native than mine, especially when it comes to computers, their software and the internet, I will quite happily ask my granddad for help when I need help with my computer software and if I ever want to use a good photo printer I always go round and use his! He's always using email to keep in touch with people as well as his mobile phone.
It is obviously true that like anyone of his age (Digital Immigrants) he has had to learn how to use all this equipment, but the fact that he knows more about it than most of digital natives I know, means that he must therefore fit into the digital native category as well....??? Should it really all be down to your age as to which category you are put under.