About 103,000 US citizens visited Cuba in 1998. The majority did so legally (most went with organized groups), while the rest slipped in through third countries and spent freely without a license. The US government has recently sought to tighten control of unsanctioned travel. Since May 1998, persons subject to US jurisdiction who travel to Cuba without a license bear a "presumption of guilt" and may be required to show documentation that all expenses incurred were paid by a third party not subject to US law.