On the face of it no, as they have an annual pass so they should in theory be able to go as much as they like. My non-evidence based suspicion however, is that some of these people who are turning up 3-4 times in a week to the same place when you've clearly had to book a couple of weeks in advance have probably block booked the whole week and then just turned up on the 3-4 that were convenient when it came to the time (therefore taking an allocated space for another passholder to use out of the system that someone else could have used). As I say, totally unfounded accusation but I've lived on this earth for 38 years and I have a good suspicion of what people are like.