What would it mean when someone says 'be careful' of him?

Anonymous
As in there's a guy who's a player and he constantly finds a way to contact a girl, (even when she blocks his number)
And she gets told to 'be careful' of him.. what would it mean?
I know it's obvious, but I'm asking cause this guy isn't the type to cause harm or be violent or anything so what else could the reason be?
He may cause harm
He may get obsessive and stalk
He may spread rumors
Other?
Select gender and age to cast your vote:
Updates
+1 y
He's also known as 'the creep'
What would it mean when someone says 'be careful' of him?
3 Opinion