I've read that it's tied to a particular grand jury session, which is something like 18 months.
Either way, the longest contempt sentence ever was 14 years, which is nothing compared to what you'll get if the government convicts you of laundering money, selling drugs, possessing child porn, or all the other crimes that you might have documented on your computer.
Because I believe in the right of a person to be secure in his papers. If you've done something illegal, the government should be able to make its case without needing your computer. If they can't, what you've done is, to me, not illegal. The people that wrote the Constitution seem to agree.
Either way, the longest contempt sentence ever was 14 years, which is nothing compared to what you'll get if the government convicts you of laundering money, selling drugs, possessing child porn, or all the other crimes that you might have documented on your computer.