Every addict is going to show up to defend it.
Truly. Some responses on this thread have been pretty predictable.
One of the most common is "But what about these GREATER ISSUES" (accompanied by a sweeping gesture), which demonstrates avoidance of God's requirement for personal, individual purity and responsibility. It reminds me of Christ's conversation with the woman at the well. She wanted to talk about locations of worship (abstract, "greater" issues), He wanted to steer the conversation back to her own personal responsibility.
It all starts with the individual.
I wonder how many men out there, who would otherwise be in satisfactory (if not wildly happy) marriages, have been detoured by pornography. Plain Jane who lives a modest life is no match for Video Vixen or Centerfold Cathy.