Fraudulent charities, donations to

What with that guy pleading guilty to racketeering regarding his allegedly fraudulent charity, I got to wondering whether people who unwittingly donated to such a charity and claimed the benefits of the donation on their income tax are potentially subject to penalty. I would imagine that anyone who knowingly donated to a “terrorist-front” charity or any scam charity (“terrorist front” or not) would be subject to criminal and civil penalties (i.e. racketeering or money laundering). I can’t imagine filing criminal charges against an unwitting donor but could they be dinged by the IRS?