The safe and effective method would involve library developers joining hands, defining a single watermark decode protocol and having it linked to places like YouTube and Soundcloud.
So basically, whenever one who use piracy samples or plugins upload anything on these popular sites, the server checks for blacklisted costumer identifiers and turns down upload.
This would mean paying for the technology, paying YT/SC for their service.
This system will be put into practice before 2020.