SpigotMC is a website for modding, server plugins and other minecraft related content.
When a user signs up for SpigotMC they create a profile and some people include their Date of Birth and location.
To search for a user, use the search box on the front page. The search results will show all the posts any user by that name has made, but on the right hand column at the bottom it will show username matches. In this example I searched “md_5” (the SpigotMC administrator). You can see in the bottom right, md_5 shows up as a user.
Clicking the username will pop up a mini profile, but what you want to do is click the “Profile Page” link in that box.
Here’s an example of a different users profile. You can see in the left column at the bottom, there is a box that contains profile information
Here’s a larger view of the box:
So from this you can see their age and location. You can then compare that age and location to the whitelist information provided.