Emotionalism. We are all susceptible. But too often this is the excuse for initiating force, or even (shudder) calling for government to stick it to ... whoever we are emotional over. Or, it can be expressed by defending- against all reason- someone who is a real bad guy, but whom we "like" for one reason or another (this I'll discuss in Part 2).
I often see the irrational "super-hatred" aimed at "sex offenders".
Most of the time, but not always, this emotionalism is due to people being "too close" to the issue. Maybe a "sex offender" abused them, or scared them, or they are worried about that sort of thing potentially happening more than most people are. Unless you or someone you know has been violently violated in a sexual way, I think this "super-hate" gives sex a magical mystical quality that it doesn't really have, probably due to a certain degree of anti-sexualism or "Victorian" attitudes. Perhaps in some people's lives it does have this power, and it lacks this power in other people's lives. One size does not fit all.
Many times over the years I have watched as libertarian friends went ballistic in unlibertarian-seeming ways in their hatred of "sex offenders" who never actually initiated any force, but who lived up to the "offender" part of the label by offending someone (such as "the public").
I don't know of any other accusation where the accusation alone is sufficient to create this hatred. Not only that, but anyone who suggests that the alleged actions may not have actually happened, or may not be wrong in and of themselves gets covered by the "super-hate" along with the accused. With accusations of theft or murder, anyone recognizing that the accused may not be guilty doesn't get treated this way, and neither does the accused in most cases.
It didn't matter that I basically agreed that their conjectured or real scenarios weren't good- I apparently didn't go far enough in my hatred, and I dared see the other side- and see that accusations do not equal guilt, and that if no force was initiated, the Zero Aggression Principle wasn't violated. And, I admit I often played it up longer than necessary to see where it would go and see whether the root of the hatred would come up. It usually eventually did.
One big part of the problem is that making exceptions for government intrusion or personal initiation of force is that once you let that camel get his nose under the tent, you can't stop it from lifting his head and removing your protection completely. You only deserve the liberty you respect in others- even those you despise.
Once you stop reasoning with regards to someone, your enemies can move you just a bit further toward their position. They make it OK to hate someone for their own purposes. "Liberty doesn't deal with this issue- let us take care of it for you." Or, the non-governmental way to say this is "Well, this really offends me, so I'll say this is an initiation of force, or a credible imminent threat to initiate force, and I'll use 'defensive' force against this person. It's OK. Really."
In either case, there is a danger of "mission creep". Actually, let me re-phrase that- there is probably a guarantee of "mission creep". More things will either "need" government "help" or will be called "aggression", so the justifications will get easier. It's not just a slippery slope; it's one you willingly ran toward and jumped down. And, bit by bit, your liberty is destroyed.