Solution:
If the data is published, it’s visible and accessible to everyone on the Internet. This includes the people you want to see it and the people you don’t.
You can’t have it both ways. You can make it so that data can only be visible with an account, and people will make accounts to slurp the data. You can make it so that the data can only be visible from approved IP addresses, and people will go through the steps to acquire approval before slurping it.
Yes, you can make it hard to get, but if you want it to be convenient for typical users you need to make it convenient for malicious ones as well.