Another place to find "alien signals" back in the day were in comic book shops and card shops (those that sold various sports cards). They'd almost always have

Another place to find "alien signals" back in the day were in comic book shops and card shops (those that sold various sports cards). They'd almost always have sections of weird periodicals that were made by completely unknown people. We used to share them at school, full of inappropriate content that would probably get kids expelled these days. Also things like the Anarchist Cookbook (and similar collections) which felt extremely illegal at the time, but you can pick it up on Amazon now. I remember one that was dedicated to gruesome crime scene photos and detailed descriptions of horrific crimes. Half the pictures looked like photocopies of photocopies, which is far less jarring than what you can find online these days.