As we've written in Intro to Squirrels 102: Proper Care of an Orphaned Squirrel, it's best that humans do not directly interact with squirrels. We recommend enjoying squirrel watching from the distance.
But on some occasions, squirrels are the ones that inst igate interactions with humans. There is an August 2006 case of an overly aggressive squirrel that was attacking people in Central Park in the Orlando are near Rollins College in the town of Winter Park. The following was written in the 8/11/06 Orlando Sentinel:
At least seven people were attacked by an abnormally aggressive squirrel in Central Park from Aug. 1 to Aug. 4. The squirrel attacked people on four consecutive days, persisting despite being smacked with a purse and shoes, pepper-sprayed by police, stomped and flung.
The squirrel's victims had expressed frustration that it was not captured sooner, especially after hearing that 19-year-old Dylan Osborne had caught it Aug. 3 and held it under a bucket for more than two hours waiting for county animal services to arrive. Osborne released it when no one came.
A short time later, it scratched Shannon Mariotti's foot while she sat on a park bench. Mariotti, 29, had just arrived in Winter Park hours earlier to begin her job as an assistant political-science professor at Rollins College. "I started to walk away from it, and it followed," she said. "Then I started to run away, and it ran after me." As she ran from the park, she tried to warn Cox, but the squirrel quickly latched onto Carson, biting and scratching him. Mariotti and Carson began rabies treatment that night at a hospital emergency room.
What did this happen? A wildlife expert postulates the squirrel became accustomed to being fed by humans.
Joe Perez of Orlando-based Advanced Wildlife Trappers speculated that the squirrel was accustomed to being fed by people and was looking for food, even if the victims had not been feeding it. "They get very aggressive," Perez said. "They will come after you for something to eat."
Again, we recommend squirrel watching from a distance, but these people did nothing wrong.