bill of attainder
No, a Bill of Attainder is the legislature simply declaring guilt of a person/group.
I think this is more a fifth amendment issue:
Amendment VThough that's shaky, as there's no current criminal case; but insisting that the compelling to produce the evidence with which to bring a criminal case is certainly going against the spirit of the law... besides, one could argue that being compelled to furnish the alleged evidence of wrongdoing is testifying against yourself in a criminal case even if such hasn't yet gotten a case-number and docket.
No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
zactly