Although IRS official Lois Lerner has formally invoked her fifth amendment right against self-incrimination, she is obviously still in contempt. In this case, Lerner is not in danger of imminent criminal prosecution, but is instead covering up IRS practices of targeting political groups. It seems she is merely looking for a way to avoid testifying in a glaring misuse of power.
Only Congress has the authority to say what "contempt of Congress" means. (The Constitution gives Congress the sole authority to determine qualifications of its own members, too). Congress has many times misused its contempt powers; during the Red Scare of the 1950s, there was even an extralegal element by which people were denied their jobs. But only Congress can legally specify what contempt of Congress is.
When it come for working for the Government, the people that we rely on everyday, and who we have no choice but to trust, Lerner should have to answer a question as such, because it's only fair that people know what's going on about their information, the IRS knows enough about us, so why should it be so secretive as to find out what they have been up to.
Frankly, I'm in contempt of Darrell Issa's witch hunt. Issa has behaved in an autocratic manner and is clearly motivated by a desire to make trouble for the Obama administration, rather than an unbiased desire to get to the truth of the matter. Lerner took the 5th, as is her right, and that should be the end of it.