Teams need feedback, and boundaries. We want to have in a collaborative culture. One with high trust.
It is important that we do not tolerate, condone, or otherwise support when we see or hear toxic behaviors. Here is a link that helps explain toxic behaviors and their effect on teams here http://www.beyondtheleadingedge.com/192/leading-edge-news/teams/the-four-team-toxins/ . I first learned about this model from Lyssa Adkins – it provides a powerful lens for surfacing team challenges.
When you see Team Toxins, please give feedback privately to the person. Or come and talk with your manager or a trusted coach so that they can help you address.
One good model for giving feedback is http://www.manager-tools.com/2006/10/the-peer-feedback-model .