This is not a criminal case against these lawyers, though. This is a continuation of a lawsuit that they filed. The judge essentially said that he was summoning

This is not a criminal case against these lawyers, though. This is a continuation of a lawsuit that they filed. The judge essentially said that he was summoning them to court to explain how the business arrangement that they had set up and the suits they were filing was not an attempt to defraud the court and abuse the legal system. Since they declined to explain anything, they may be subject to such consequences as being disbarred or being fined for court costs. Since it is not a criminal or even civil trial against them, the rules are different, but there is no direct possibility of jail time or punitive fines. Now, the judge could very well refer the case to the US Attorney, in which case criminal charges could be filed against any or all of the attorneys/employees in question. In any trials ensuing from such charges, pleading the 5th cannot be used as evidence against them, but there would presumably be plenty of other evidence to demonstrate their guilt.