No idea why this is downvoted; it's the plain truth. The same thing goes for other sanctioned countries: (Cuba, North Korea, Sudan, and Syria), as well as for transactions mentioning sanctioned individuals or organizations.
Is Cuba still sanctioned? I thought the main embargo was lifted a few years ago.
Cuba was removed from the State Sponsors of Terrorism list in 2015, but it remains under heavy economic sanctions and travel restrictions -- enough so that mentioning "Cuba" or "Havana" in an electronic payment memo will probably get your account locked temporarily while the compliance department takes a look at it.