no, they don't target fish, or fisherman..
( I think most anyone who has surf fished, the backside of the cape, has experienced the "being followed" by them)...
and when their numbers are up, they tend to get aggressive...if you live in an area and only see a few, they seem timid.. when the polulation gets as high as is it on the cape, their demeanor changes... be it strength in numbers, or just the added cometition for food, and it is hunger motivated.. they are nasty disease ridden sea rats, and don't ever forget that, no matter how "cute" they look.