Paper terrorism is when someone uses legal-sounding documents and processes in a mean and tricky way, to bother, scare or hurt other people.
It's like playing a bad game of pretend, where someone makes up rules that aren't real and don't make any sense, and then they try to trick others into believing those rules. And instead of everyone having fun, they just feel upset and confused.
These fake-looking documents are used to try to make people do things, or to trick them into thinking they have to do things, that they don't really have to. For example, someone might make a fake-looking ticket or court order and give it to their neighbor, saying they have to pay a big fine or go to jail.
This can be really scary and frustrating for the people who receive these fake documents, because they might think it's real and that something really bad is going to happen to them. They might spend a lot of time and money trying to figure it all out, and they might even get into trouble with the law if they don't respond to the fake documents in the way the bad guy wants them to.
So paper terrorism is a very bad and mean thing to do, and it can really cause harm to people.