Yes, but I'm not so much interested (right now) in what are the optimal rules to impose on people; I'm asking what is the right thing to do, which is a subtly different question. Your argument that eviction leads to problems in other places is clearly true. Analogously, it would be a very bad idea to impose a 80% marginal tax rate on top earners to fund the Against Malaria Foundation, because most of them would work less and there would be huge deadweight loss. However, Peter Singer and people like that argue persuasively that very wealthy people should as a matter of principle voluntarily give a high percentage of their income to efficient charity. And this causes no deadweight loss if they make sure to work as much as before.
Similarly, if there are creeps in your group, don't you wish they would just leave, and not try to infiltrate another innocent group? Then that is what they should do.
Analogously, it would be a very bad idea to impose a 80% marginal tax rate on top earners to fund the Against Malaria Foundation, because most of them would work less and there would be huge deadweight loss.
The tax rate was 90 percent on them for a long time, in the US -- what's your basis for that claim? It sounds like a cached belief.
One of the lessons highlighted in the thread "Less Wrong NYC: Case Study of a Successful Rationalist Chapter" is Gender ratio matters.
There have recently been a number of articles addressing one social skills issue that might be affecting this, from the perspective of a geeky/sciencefiction community with similar attributes to LessWrong, and I want to link to these, not just so the people potentially causing problems get to read them, but also so everyone else knows the resource is there and has a name for the problem, which may facilitate wider discussion and make it easier for others to know when to point towards the resources those who would benefit by them.
However before I do, in the light of RedRobot's comment in the "Of Gender and Rationality" thread, I'd like to echo a sentiment from one of the articles, that people exhibiting this behaviour may be of any gender and may victimise upon any gender. And so, while it may be correlated with a particular gender, it is the behaviour that should be focused upon, and turning this thread into bashing of one gender (or defensiveness against perceived bashing) would be unhelpful.
Ok, disclaimers out of the way, here are the links:
Some of those raise deeper issues about rape culture and audience as enabler, but the TLDR summary is:
EDITED TO ADD:
Despite the way some of the links are framed as being addressed to creepers, this post is aimed at least as much at the community as a whole, intended to trigger a discussion on how the community should best go about handling such a problem once identified, with the TLDR being "set of restraints to place on someone who is burning the commons", rather that a complete description that guarantees that anyone who doesn't meet it isn't creepy. (Thank you to jsteinhardt for clearly verbalising the misinterpretation - for discussion see his reply to this post)