Stuff like this is so difficult because it's so much fun - but once it goes viral online it becomes an issue when everyone wants to do it. These types of interactions can be great, but can get out of hand quickly.
For example - a friend of mine went to another large haunt in the past, and there was a group of vampire characters surrounding us. My friend told them to stay back because he had garlic in his pocket, and they all screamed and ran back to their hiding spots.
Interactions like that are great for the guest and likely fun for the actor as well, but it just has so much potential to get out of hand in the age of social media.