Earlier quoted context omitted.
Nope, intent isn't magic. http://genderbitch.wordpress.com/2010/01/23/intent-its-fucki... And puerile male humor is often intended to drive women away from the boys' club.
http://en.wikipedia.org/wiki/Mens_rea intent isn't magical but it is legally meaningful. if our laws recognize that intent matters maybe you ought to also.
Intent doesn't always matter, and in this case of puerile humor it doesn't matter.
The world could be 99% white, and if I spoke from the perspective of a white person, as if white people are God's gift to humans, I'd be insensitive to the 1% of non-white people. I'd be instilling in the minds of non-white children growing up thinking somehow they are worth less, and are lesser human beings. The whole point of political correctness is that you don't have to actively say negative things about other people, races, or religions to have a negative effect on them.
I may not have intended it because of ignorance. I may not have intended it because I have never met a non-white person, and everyone I've met has not been offended by it. But that does not mean my actions are without real consequences to non-white people who happen to hear me when passing by, or from normalizing this action so that later other white people end up adopting this attitude in front of non-white people.
The titstare app is pure and simple objectification of women. That 9 year old programmer is coming into an industry and shown that the most interesting thing about her will probably be trumped by her breasts. She's being placed into a culture she can't genuinely adopt (unless she's bisexual or lesbian) because she's not a man. This is alienation. It may not be intentional, but it does have negative effects due to ignorance.