  We review the theoretical efforts to understand why pre-main-sequence stars
spin much more slowly than expected. The first idea put forward was that
massive stellar winds may remove substantial angular momentum. Since then, it
has become clear that the magnetic interaction between the stars and their
accretion disks explains many of the observed emission properties. The disk
locking scenario, which assumes the magnetic star-disk interaction also solves
the stellar spin problem, has received the most attention in the literature to
date. However, recent considerations suggest that the torques in the star-disk
interaction are insufficient for disk locking to explain the slow rotators.
This prompts us to revisit stellar winds, and we conclude that stellar winds,
working in conjunction with magnetospheric accretion, are a promising candidate
for solving the angular momentum problem. We suggest future directions for both
observations and theory, to help shed light on this issue.
