The New York Mafia runs illegal rackets...Scams, protection, union deals, gambling, drug distribution, prostitution, etc. Most of their activities are unlawful and there are efforts made by law enforcement to control such activities.
Wall Street does not violate many laws because our legislators and regulators are paid not to write laws that protect the average investor. The only illegal activity that gets much attention is insider trading. Candidly speaking, if you aren't getting profitable tips and you are working on Wall Street, you are either very honest or very stupid. I strongly believe that the "real" profit made in the finance industry stays in New York or is transferred to off-shore accounts.
I am not knowledgeable relative to Mafia involvement with Wall Street. If I had knowledge, I can assure you that I wouldn't paint a bulls' eye on my chest by posting it here. Smarter folks than I are paid generous salaries to seek out those types of connections. Plus, they have subpoena powers and body guards.