Deindividuation: It's more likely than you think.

Check out [ http://youarenotsosmart.com/2011/02/10/deindividuation/ ].

The whole youarenotsosmart blog is actually a really good read, to be frank.

Groupthink causes serious issues- on design teams, especially. When ideas are quashed because they don't fit the ideals of the hivemind, it silences creativity and further enforces groupthink ideals.

Deindividuation is serious business- and you should be looking out for yourself and others, stopping it before it happens.