This is a function of security that keeps our sites from being scraped for data. These throttling rules are different depending on the role of the site visitor. The rules are based on the number of lookups done in a certain period of time. A logged in user will have more lenient rules associated with their account.
If a logged in user is consistently running up against the limit, we'd like to understand how they are using the tool before those rules are adjusted. For example, a user recently reported the same issue and, after chatting, I found that the user was looking up every item on his submission to get grading results. He was not aware that he had access to grades on the submission tracking page.
If you are a user who is logged in and consistently running up against the limit, let me know how you are using the tool so we can make an informed decision about how to proceed. If we can avoid it, we don't want to sacrifice security to open the door for harvesting data. With that said, if adjusting the throttling limits is the only solution, we are not against it.