Given a travel related situation, and given a specific question about the situation, summarize the question into a title

Input: Consider Input: I had an uncanny feeling that it was rude of me to talk on a mobile phone for the whole journey, while travelling alone in a London black taxi. Is it the etiquette to have a conversation with the indeed highly qualified driver when travelling alone in a London black taxi? What should I do if I am on a business meeting on my mobile phone for the whole journey?

Output: Is it rude to talk on a mobile phone for the whole journey, when travelling alone in a London black taxi?

Input: Consider Input: When paying by card flight attendants usually ask to see your ID, to verify that the card in fact belongs to you. However it seems weird to me that pretty much no other merchants ever ask to see your ID, even when conducting purchases for thousands of euros (e.g. at IKEA).

So why do airlines insist on verifying your ID when paying by card? I understand that there's (usually) no Internet to verify the card balance on the plane (as suggested by TonyK), but how would one's ID help them out in case the card is empty?

Output: Why do flight attendants ask to see your ID when paying by card on the airplane?

Input: Consider Input: As seen in the Politics SE:

Right now, you can jump on a ferry in France, head over to Cork, drive up to Belfast and catch the ferry to Liverpool, without ever showing your passport to anyone. It seems inconceivable that this arrangement could be maintained if and when the UK leaves the EU.

Best I'm aware you'd need to show your passport before boarding in France, in much the same way that you do when taking the Eurostar to London. Because Ireland, like the UK, isn't part of the Schengen zone.

Which is it?

Bonus question: would you also need to show your passport to go from Belfast to Liverpool, or is that second assertion factual?
Output: Do you need a passport to take the ferry from France to Ireland?