They aren't really to the age where pornography is an issue yet. My oldest boy is 12.
I think the biggest problem is the social pressures of "trying to keep up with the Jonses" when looking at FB and Instagram. You see all of the great things everyone else is doing and has and you don't see anything negative (other than the occasional passive aggressive "OMG NOT AGAIN!" type things on FB).
As one person described it: "You're comparing your every day life to someone else's highlight reel".
I am proud of my oldest, who is my only girl. Girls have unique peer pressures that I think are magnified by social media. She's 19 and seems very well adjusted and happy and she had a cell phone starting in the 8th grade because of all the dance she was doing. Although, I don't think got a real smart phone until sometime in high school.