Another racket for Mob-dominated unions is "rulebook slowdowns":

A contractor must finish a big office building within a specified time period. If he's late, he has to pay huge penalties for each day behind schedule. So, if he refuses to cooperate with the Mob (not doing business with their suppliers, not providing no-show jobs, etc.), Mob guys will demand that every little-bitty rule of safety, procedure, seniority, etc., must be followed at the construction site. For example:
--The Mobbed-up union rep will insist that every truck entering the site be minutely inspected for "safety," so as not to "endanger" the workers;
--Ordinarily, workers will jump at the chance to work overtime because they're paid more per hour. But, the Mobbed-up union will insist that workers not accept overtime assignments; or that overtime be offered only to workers with maximum seniority.

You get the idea...

Another big source of union/Mob corruption is contributions to political campaigns from union treasuries, and turning out union members to work for, and vote for, political candidates. Then they call in the favors.