Are offshore carriers responsible for spam calls that spoof numbers (based on your data)? Those two carriers are onshore so I think they would have to comply wi

Are offshore carriers responsible for spam calls that spoof numbers (based on your data)? Those two carriers are onshore so I think they would have to comply with the SHAKEN/STIR protocol which would make calls originating from their network easier to identify and block. Offshore carriers don't have those restrictions. I am surprised a company is able to operate like this onshore.