I personally have never had to participate in this practice, but know plenty of people who have.
Be careful for any of you who pay to have someone stamp your passport for you either at the panama or Nicaragua borders.
http://insidecostarica.com/2015/05/22/c ... -tourists/I will also try to find the link to the advisory from the U.S. State Department asking for assistance particularly at the Nicaragua PeƱas Blancas crossing when people are "illegally forcing" you to spend three days before returning to Costa Rica.