I’ve changed the way memberships of a board are managed. Previously memberships were determined when importing a Bitbucket repository. This resulted in all member of the repository being imported getting an account on Bitboard. This was of course not a great solution, but it was good enough in the beginning. But now I have changed it so that the board owner must invite members explicitly in the board settings page. An email will be sent to the email specified with a unique link granting access to the board.