Yes, fans of old didn't identify so much with their idol. They idolized them, certainly, but they weren't as obsessive and compulsive as they are now.I think a significant difference between the punk fans of yore (or even today) and Swifties is that punk fans tend to take pride in being subversive. When people tell punk fans they don't care for punk music, they tend to wear it as a badge of honor - they've found something to love that everyone doesn't appreciate. On the other hand, Swifties tend to react to finding out someone doesn't like her music as a personal attack - as if my not sharing their music taste somehow implies I don't think they can/should like it.
As far as danger goes -- she's got ex boyfriends who have received death threats. Fortunately, they have not been carried out. But when a swarm of fans decides that a man is an enemy because he no longer dates Taylor, it's kind of creepy or scary.
Now, they think they know their idol, they think their idol cares about them on a personal level - these fans are overly involved and attached and some even think they are going through similar situations such as a boyfriend breakup when in reality these fans have almost nothing in common with the person they worship.