I have heard many comments on facebook (on both sides)concerning Driscoll's way of using harsh words from the pulpit - especially as he goes after hypocrites. Here is a video where he explains his rationale.
He also seeks to give a biblical defense of using sharp words in a lecture he gave in Minneapolis last September at the Desiring God Conference - "How Sharp the Edge? Christ, Controversy and Cutting Words." I especially enjoyed the last 20 minutes where he exhorts church members to watch how you talk about pastors and pleads with them to pray for us.
I know that many object to Driscoll's reasons for harsh words like - "well, Driscoll is no OT prophet nor is he like Jesus (both used sarcasm and crude words to attack hypocritical religious people)." Douglas Wilson has some good points on this subject in a post called "A Temporizing Baa-Lamb." If you have taken enough time to criticize Driscoll, please take the time to read Wilson and listen to Driscoll's sermon on Words. I do think Driscoll goes to far sometimes, but I am not in his shoes and I am far too often a people pleaser.