You can install an anti-spam filter on your landline by connecting a modem on the landline. A modem allows you to control the phone-line programmatically: if th

You can install an anti-spam filter on your landline by connecting a modem on the landline. A modem allows you to control the phone-line programmatically: if the number is unwanted, just let your program to hang it up. Software like NCID (http://ncid.sourceforge.net/ http://ncid.sourceforge.net/) provides a solution for interpreting the Caller-ID of the incoming calls. Even better, because the modem only rejects incoming calls, it won't interfere with your phone. You can continue using it as usual. All can be done on a Raspberry Pi. https://murphy101blog.wordpress.com/2013/11/03/raspberry-pi-telephone-number-blocker/ https://murphy101blog.wordpress.com/2013/11/03/raspberry-pi-...