"May" is the keyword there. Also there may not be elephants in a city, while there may be terrorists on planes (I think some incident happened in the past, but

"May" is the keyword there. Also there may not be elephants in a city, while there may be terrorists on planes (I think some incident happened in the past, but I'm unsure). The conclusion is that it's unknown, and calls for a proper evaluation of the matter. The argument by itself is useless. Why are you using a seat belt to prevent mortal incidents, when there aren't mortal incidents with seat belts?