Attack of the killer squirrels...

I am trying to plan a trip to Southern California later in the summer and it reminded me of a story.

I was a senior in high school and I was driving to San Diego to visit my grandparents. I had picked up lunch earlier that day because I planned on stopping somewhere and having a picnic lunch. I decided to stop at Mono Lake park. I grabbed my lunch, a blanket and a book. I headed for the grassy park area. I laid down the blanket and set my lunch down. Before I even sat down I noticed the squirrels all over the park had started heading my direction. I sat down and pulled out my sandwich. The squirrels were getting closer. I opened my sandwich. By this time there were probably about 15 squirrels all around the edge of my blanket. I tried shooing them away. I think that just spread the scent of my sandwich because, before I knew what was happening, almost the entire edge of my blanket was lined with squirrels. They wouldn't come on the blanket, they just sat right on the edge. I had no idea what to do but I started freaking out, picturing my dead body covered in squirrels with pieces of the sandwich thrown about. There were so many of them! I finally decided the only way out was to try throwing my sandwich away from my blanket and then running for the car... I proceeded to throw bits and pieces of crust in all directions to try and lure the squirrels away. No luck, the squirrels held their posts. I finally decided to try throwing the entire sandwich away from me...the squirrels ran after it. I grabbed the blanket, the book and I ran.

Do you think the squirrels there are used to being feed?