Who is U2?
whoisu2.com
whoisu2.com
It amazes me how people, even young ones, can be so out of touch with culture. Whether you like U2 or not, if you grew up in the western world and you're above the age of 14 (which most these people seem like), you know, or now what, U2 is.
Here is something interesting: http://musicmachinery.com/2014/02/13/age-specific-listening/
I have to say though, they did one of the biggest grossing tours, if not THE biggest tour, in history of music between 2009 and 2011: http://en.wikipedia.org/wiki/U2_360%C2%B0_Tour
To be honest, at the age of around 14 today you should at least know "what" U2 is even thought you've never listed to or heard any or their music.
They're clearly not a memorable band, contrarily to the Beatles (whether you appreciate them or not) or the Pink Floyds.
(I'm 50 years old, so it's not a question of age).