unsolicited request to join workspace board

[Leslie Jakobs]

As admin, I recently received a request to join a board restricted to Workspace members. No members on the workspace have never heard of this person, nor was this person given any details on the board.

This is a bit unnerving. How did this person find me/this board when the visibility is set to Workspace? And what can we do about it?

[Michael Pryor]

"How did this person find me/this board when the visibility is set to Workspace?" 

Someone who had access to the url of the board either sent the url to someone (email, facebook, etc) or put it somewhere where the person found it (or it was open on a public computer somewhere).  Regardless, if the person shouldn't have access then just deny the request or ignore it and the person will not get access.  There isn't anything else for you to do.