As a privacy-conscious lawyer, I keep noticing how much personal information gets exchanged before a conversation that may last twenty minutes and never happen again. A phone number, email address, contact record, calendar identity, and sometimes an account can turn a temporary interaction into a durable relationship in several databases.
The principle I keep coming back to is data minimization: disclose what the conversation requires, not everything that makes future tracking convenient. PapaCall (https://papacall.me) is one example I came across while thinking about temporary communication, though the broader question matters more than any particular service.
Should a one-off call be allowed to remain genuinely one-off, and how much personal information are we giving away simply because modern communication tools make permanence the default?