Although it doesn’t look like any furloughed Federal worker will be prosecuted, the Office of Government Ethics has published a “reminder” in the case of further shutdowns aimed particularly at those who crowdfunded some of their missing salaries.
In fact, the OGE noted that crowdfunding sites pose particular traps since the ethics rules say a federal “employee may not accept any gift given (1) because of the employee’s official position or (2) from a prohibited source.”
Moreover, you can’t accept a free meal (eg, from Jose Andres) “as long as the offer is extended to all federal employees” but not just to furloughed employees.
And those no interest loans offered by your (Federal!) credit union, not good unless offered to all Federal employees.
Consider yourself warned now!
The ethics opinion is here: https://www.oge.gov/web/OGE.nsf/All+Advisories/9D4E04812177E26C852583A2005856F0/$FILE/LA-19-01.pdf?open