Yes, the copy/paste- plagiarism rule is strictly enforced and there is a trove of volunteers sifting through posts to bust people. There is not a statute of limitation on an offending post. Now that you know the reason, you can follow the instructions in your ban message and attempt an appeal. Unfortunately, the chances that your ban will be lifted are slim. You may want to lock this thread now that you know. I can practically hear the mob coming.