Are you referring to what was learned from the immoral acts, or doing the immoral acts? The immoral acts are always wrong, no matter what. Using information acquired from these acts is stepping into dangerous territory. An example I can think of is the studies involving pre-marital sex. These studies are always immoral, but the information learned can be used to convince other that abstinence is the way to go (no sources on hand, but we’ve all heard “multiple partners increases your risk of STDs” and the like)
To go purely on opinion, I do not think it is wrong to use such information. However, until I get a firm answer, I will refrain from doing so.