I think that if you take the 5th and refuse to answer on the grounds that your answer my incriminate you....the grand jury can offer you immunity. Then you are compelled to answer questions, and if you don't, then you can be tossed in jail for contempt of court. I believe this is what happened to Greg Anderson in the Barry Bonds case.
That's exactly how immunity works, and they use it at Grand Juries all the time to get "little fish" to offer testimony about "bigger fish." They employ this tactic mostly with shylock debtors and gamblers who are in over their heads, and it's hardly fair.
Example: You're a gambler into a couple of bookmakers and a shy or two. Your name gets picked up on a bug or wiretap because bookies and shylocks just can't help complaining about the money they have owed to them. You get called to the Grand Jury, where the very friendly assistant district attorney explains to you that you're not the "target" of this investigation, so if you have nothing to hide you should just tell the truth. At that point, you probably invoke the Fifth Amendment and the assistant district attorney isn't so friendly anymore. He tells you to come back in a week or so and he produces an immunity order, at which time you're forced to either:
a) tell the truth about some bad guys and put your well being in danger.
b) lie your ass off and risk a perjury charge.
or
c) stick to your guns and take the Fifth, at which time you'll immediately be jailed UNTIL THE GRAND JURY IS DONE CONVENING. And in the Federal system "special" Grand Juries can convene for over a year, sometimes even longer.
It's a terribly slanted system which stacks the deck against the little guy. And ironically, we got the Grand Jury model from England, who did away with it a long time ago. We should have followed suit.
