If financial gain is a side benefit. What do you think the primary benefit is?
But sadism is very rare, in reality. Most robbers don't give the rubies they steal to the village children. Most galloping animals with four hooves are horses, not zebras.
But the power of the internet can magnify the effect of a single sadist to the point that it affects a million people (up to the limited extent that such opportunities exist).
Just my thoughts