It seems that the people down at Niantic have changed how PokéStops work once again. Now it seems that when you spin a stop you no longer get the experience if your bag is full. This might not seem like a big deal to many players since stops only give out fifty experience points, but there are many players who are a very high level and rely on grinding to get up levels quickly. It also gives players who are passengers in vehicles less to do while riding around. However, this might convince some players to stop spinning and driving.