This thread should be posted in response to every "I want to paint my brick white" post.

Find an out of the way spot to experiment with paint stripper and/or heat gun. The above poster had good luck with removal but your mileage may vary. Is this an old house or more recent? If the former, the old early 1900s brick may be too soft/crumbly (simply due to how it was made) and possibly would not survive harsh chemicals or power washing. On the other hand if you were to just get the paint film off of the surface and then leave whatever white paint still remains deep in the pores, that could give you an attractive look. Actually it would be exactly the same aged, worn whitewashed look that is so fashionable nowadays, only you will have achieved it by removing paint, not adding it on... Well it's a thought.