By 'taking them on' I only meant putting out another counter argument at least once. If somebody doesn't say something, the offending person might think incorrectly that since nobody is disagreeing, everyone agrees with them.I'm not sure what you mean by "taking them on." I think you have to pick your battles. At least that's what I've found in my experience. Most people who are truly "vindictive and vitriolic" will only be further provoked by anyone who has the audacity to suggest that there might be another perspective worth considering. I tend to "take them on" (if I'm understanding you correctly) only until it becomes clear to me that we're going around in circles and it's never going to stop. If a dispute or difference of opinion seems to have some possible resolution, then I'll continue trying to reason with the person.