Punk is a label with a meaning. To me, punk is about being non popular. If punk were popular, you wouldn't think of it as rebellious music. Just as it's not rebellious to write with a pen, or walk, or eat. Everyone does it.
Punk is about being something different.
Something that questions mainstream society. Blink 182 considers themselves to be Punk Rock. Get a life. Blink is good at what they do, but what they do is not punk rock. Once they consider themselves Power-Pop or something without the word Punk in it, I will have no problem with them.