As Valerie Aurora[a] writes, there's some problems with harassment at DEFCON[b], the computer security conference.
There is irony in the fact that a conference for security professionals can't guarantee the security of the people there.
What isn't ironic, however, is that a conference about security also attracts people who are more interested in violating other people's security than providing it. That's just a sad fact of human nature.
They should not be given sanctuary. Otherwise, we just help them by giving them a respectable title to hide behind.