Joke Collection Website - Blessing messages - How is it that mobile phones often receive strange calls and text messages?

How is it that mobile phones often receive strange calls and text messages?

If it's an advertisement, send it by number, regardless of the specific number.

If it is recycled and put back, others will use it, and they don't know how to change the number.

There is also a mobile salesman. Everyone has a catalog. When applying for a new one, in order to identify whether this number is used, it is usually dialed once and then pressed to indicate that it has been used.

There is no need to change the number.

Probably the same.

Stick to it, and there will be fewer harassing calls.