A lot of corporations do under the table dealings with unlawfuls. However this is true of nearly every corporation so I suppose its less important than the 'main' ones. OS&C has more dealings with unlawful groups than most corporations however.
Not to mention their 'strength' is the ability to blackmail any senator or politician in Sirius. But it really comes down to what do you define as quasi-lawful. OS&C doesn't participate in unlawful acts itself, it just funds groups that do.
