Casey Nocket, 23, has pleaded guilty this week in federal court to several acts of vandalism in national parks.

In 2014, the self-described artist painted over rock formations in parks such as Yosemite, Crater Lake and Death Valley, then Instagrammed her work.

That's where she caught the attention of Casey Schreiner, founder of Modern Hiker, who publicized the acts to alert the public.

Schreiner joins Take Two about how park vandalism goes beyond just one person, and what other visitors can do when they see someone being reckless.