Being a striker does give additional legal rights you wouldn't other wise have, but I don't think that this is one of them. It's also unclear whether the author or people using the script are actually fired employees or bored teenagers jumping on the bandwagon.

Spamming a police department with fake tips is specifically illegal (making a false police report and/or obstruction of justice and/or USC 1001). I'm not sure about fake appointments for a hospital, that seems the most unclear of the cases you've listed.