I'm not sure exactly what the 'safe distance' rule for wildlife in Yellowstone National Park is, but I'm positive these eight tourists were well within this Bison's personal bubble. Who pays for the indiscretion? Of course the littlest of the group, maybe 10 years old, gets chased by the beast!

I did a bit of quick research and found this on the Yellowstone National Park website

Wild animals, especially females with young, are unpredictable and dangerous. Keep a safe distance from all wildlife. Each year a number of park visitors are injured by wildlife when approaching too closely. Approaching on foot within 100 yards (91 m) of bears or wolves or within 25 yards (23 m) of other wildlife is prohibited. Please use roadside pullouts when viewing wildlife. Use binoculars or telephoto lenses for safe viewing and to avoid disturbing them. By being sensitive to its needs, you will see more of an animal's natural behavior and activity. If you cause an animal to move, you are too close! It is illegal to willfully remain near or approach wildlife, including birds, within ANY distance that disturbs or displaces the animal.

According to this verbiage, the kids who can luckily outrun a Bison may have just committed his first criminal offense and it is on YouTube for everyone to see!