Here's a nice example of tu quoque. Richard Youngs is writing about Afghanistan and he says:
It might be a tall order to create a model state in Afghanistan. But we should not presume to question Afghans' aspirations to this end. The single biggest flaw of the Nato engagement has been the tendency to presume to know what Afghans want and need. State-building efforts must leave enough room for local variation. But they must not slide into a relativism that harks back to a colonial mind-set of dismissing Afghans' suitability for modern politics.
The colonial mind-set is a charge usually levelled at people who think that North Americans and Europeans have a positive role to play in Afghanistan. Youngs turns this back against those who are happy for Afghans to be spared the benefits of 'modern politics'.