While facts are not protectable, compilations are. However, it must have at least some creativity. This is a very low bar however.
To be sure, the requisite level of creativity is extremely low; even a slight amount will suffice. The vast majority of works make the grade quite easily, as they possess some creative spark, “no matter how crude, humble or obvious” it might be.
Basically, it has to be anything more than an alphabetical list of people. Categorize it or something.