Steve Crow (known as the porn king due to his various business interests) runs an event several times a year in different cities around New Zealand. This event is known as "Boobs on Bikes" and features many topless woman riding down main streets on motorcycles. The event's primary goal is to advertise Crow's erotica expos although some link them to a woman's right to expose their breasts. The donation Crow offered to the Breast Cancer Foundation was turned down because they felt that donations should not be accepted from events which are centered around porn or erotica.
Even though money will help a cause, the people in charge have to be strong about their morals and what groups they want to be associated with. "Boobs on Bikes" seems like a name that mocks the seriousness of breast cancer. On top of that, this money is coming from the porn industry. I wouldn't accept the money if I was running a foundation.