How to send a text message to a PC whose IP address I know?

I know this is a weird question, but I would like to know if there is a way to send a te开发者_如何学编程xt message to a PC whose IP address I know.

For instance, I am downloading a file through torrent from a PC on the net.

Through torrent I can know the IP address of this PC, and I want send a text message to the person who owns this PC.

Is this possible?

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The answer is No. You would have to send that through an open port on the recipients PC which a firewall would surely block (Windows Firewall, router, etc..). Even if it didn't get blocked - you'd need something to turn your message from zeros and ones to text - and display it on the users monitor. You'll need to write a software client to do that, and get that person to install it.

There are probably some black-hat techniques to do this, but again, you're talking advanced software and network penetration.