Some deplorable actions such as publishing military secrets, publishing the name of a rape victim, vile defamation, rape or murder when the victim didn't press charges, manipulating people emotionally and causing them to commit suicide, incitement of crowds, and other actions that are usually considered legal by libertarian principles, all require a non aggressive way to punish the people who performed these acts.
There are two options as far as I see it.
1. Expelling people from private lands is a good idea, but if the private lands are small (that is sidewalks, streets, parks, etc...) this is not really a viable option. You are not going to check each person who is going on your sidewalk. So what can be done about it?
2. Boycot. I'm not sure that's enough. Let's say we want to keep a known rapist out of the streets. Maybe the victim was too ashamed and didn't press charges, maybe the proof was destroyed and the rapist was not convicted by mistake. In any case we either need an extremely coordinated boycot, or some other way.
What do you think about option #1 and #2? Are there other options as well?
If you catch the rapist in the act and/or you have proof then all you can do is stop him.
Either way, there are things in any society that we cannot prevent. It all comes down to "self-defense" of the victim. Take some self-defence classes, that's it.
There is nothing deplorable about publishing the name of a rape victim anymore than there is something deplorable about publishing the name of a murder victim (personally, I don't see how anybody who isn't a misandrist could oppose publishing the names of rape victims). In the cases in which the alleged rape victim is actually a "victim" (false accuser), it is a moral imperative to publish her name so as to provide some degree of protection to men in case she will make another false accusation (I remember a story a few years ago of a Penn State football player who lost his chance to play football and a potential NFL career because of a false rape accusation by a woman who had previously made a very similar false accusation and most media outlets that covered the story still refused to publish this evil woman's name). In the case of a man accused of rape by a woman who wouldn't even press charges (and thus can't substantiate her claims), I would presume that he is innocent and that she is a liar and thus I would regard as despicable anybody who would bully him in the fashion you suggest (it seems like you are suggesting a more mild form of the lynch mob). I also do not have any objection to the publication of military secrets whatsoever.
I regard bullying of the sort you suggest as just as contemptible as defaming a person or manipulating somebody into suicide.
In the case of a murderer, I'm of the view that pressing charges is irrelevant. The murder victim is dead and therefore cannot press charges, so therefore the murder has forfeited his right to life, as far as I'm concerned, and anybody may bring a murderer to justice (although it is, of course, itself an act of murder to kill a person falsely accused of murder). I guess an exception could be made if the victim had requested that his murderer be allowed to get away with the crime (but then, it wouldn't be murder, but rather euthanasia), although I wish I could find a libertarian ground on which to prohibit euthanasia ("consensual murder").