[jamesaguilar]

I don't know if you remember, but many heads of banks were brought before congress to answer for the financial crisis. But it just turned out that many of them had not done anything illegal (or at least, not provably so).

[dredmorbius]

Congress doesn't have prosecutorial powers against citizens (it has power of impeechment against select government officials). You can be held in contempt for failure to appear, but you cannot be convicted on the basis of what is said, absent action by the courts.