In are our nation's treasures in danger what is the author's point of view about the people who damage national parks

The author of Are Our Nation's Treasures in Danger?, David George Gordon, call people who damage national parks as souvenir hunters.

They are the tourists who pick parts of the National Park as souvenir items of their trip. These items may be small but since million of tourist flock the park every year, the loss is multiplied and magnified. 

People who damage national parks are clueless that they are damaging the parks, all they wanted to do is to keep a part of the park for themselves and test the limits of the parks natural resources.