Law Enforcement is very sensitive to public opinion and even more so to civil lawsuits. The restrictions placed on me in 2010 are triple what they were in 1997 when I started. Here is a perfect example, the first video is of a fan running on the field at a Phillies game and getting tased. (An aside, the second a fan touches the field he/she has committed a crime. The longer you chase someone the higher the chance that the offender does something even more stupid than running on the field and more important the higher chance someone gets hurt. I was chasing someone and wearing the extra 40 pounds of gear and that caused an injury that cost me 9 months in recovery). The officer stopped the offender, got him off the field and no one got hurt.
The second video is an Orioles game about a month later. after the blow back from the public that the officer at the Phillies game was just too mean to the fan on the field, so they just let him go on and on till he got tired.
The Police will stop enforcing the laws when all the public cares about is the wellbeing of the criminals and turn into meter maids with guns. Oh wait isn't the national trend for the last five years showing an ever increasing number of citations issued and an equal lowering of initiated arrests? That must just be a hitch in the numbers.