I don't think knowing how to build a bio weapon means one could actually build a bio weapon. It's like saying knowing how to build a nuclear weapon can easily lead to building a nuclear weapon.
Advanced machinery and safety precaution is needed to engineer a virus or a bacteria to be a bio weapon. It's not something you can do in your tool shed at the moment. Also one would need lethal viruses to even start with and that's not something you can order off of amazon. Further, even to build a chemical weapon, the compounds needed are strictly controlled almost in every country and I would assume any suspicious purchase or order would immediately raise a flag or alert in national security service in respective country.
Advanced machinery and safety precaution is needed to engineer a virus or a bacteria to be a bio weapon. It's not something you can do in your tool shed at the moment. Also one would need lethal viruses to even start with and that's not something you can order off of amazon. Further, even to build a chemical weapon, the compounds needed are strictly controlled almost in every country and I would assume any suspicious purchase or order would immediately raise a flag or alert in national security service in respective country.