Is it harmful to pick up a strange landline number and connect to the other party without talking?

First of all, it is harmless for the other party not to talk, don't worry. Well, analyzing this kind of phone, I can tell you that the phone that looks like a landline is usually not a real landline, but an online virtual phone, with the purpose of deceiving people or selling or harassing them. The reason why you are connected, the other party doesn't talk, one may be harassment, and the other may be that the other party listens to your voice and thinks that you are not the object they want to cheat or sell goods, so they don't talk. Therefore, as long as you receive all unfamiliar fixed lines, you'd better not answer them and just ignore them. Because those calls are definitely not serious calls.