Well, they're practically tax exempt, then. It's not like you're adding a bribes line on your tax report.

And? INAL but I believe taking bribes is worse legally than not paying taxes so if you are willing to do the former, then why does the latter really matter? If you are going to take bribes, you are obviously not going to report it for fear of that second infraction because the first one would be worse and thus you wouldn't take the bribe in the first place if the latter infraction scared you.

It's kind of an "on paper" crime, a la Al Capone. You'll get caught quicker if you have a manual audit after paying bribes. The IRS keeps your returns private, for the most part, and if you don't pay you could have 10 years tacked on.