Under copyright law some parodie are considered 'fair use'; however, I would suggest that if DFU hasn't already done so, he consult w a copyright attorney (I'm not a copyright expert but there may be issues). There is an issue between copyright infringment and free speach and originality (it probably also depends a lot on the judge and/or jury if it gets that far).
Here's a link to the Stanford Univ Library that covers copyright law and fair use.
http://fairuse.stanford.edu/Copyright_and_Fair_Use_Overview/index.html
The "Pretty Woman" case in No. 115 is a good one.