This parshah deals with seminal emissions. It is interesting that no distinction is made between emissions caused by masturbation, and those resulting from “wet dreams.” We are responsible for anything that happens. Both are intentional because they were came from us. Metaphorically, we are responsible for everything that happens, whether we intended it to happen or not.
I heard from one of the rabbis that the reason Jewish men pray every day is because they might have had an emission. Metaphorically, again, they might have done something wrong and they therefore need to be cleaned.
The harm here is that many read this as literal and have guilt from their emissions, whether caused by dreams or by stimulation. The guilt is unfortunate. It is hard enough growing up and dealing with urges with no outlet.