Likewise if someone is a Japanese citizen, with official residency in Japan, and is in the US as a tourist or a student, and works remotely for a German company

Likewise if someone is a Japanese citizen, with official residency in Japan, and is in the US as a tourist or a student, and works remotely for a German company, a Canadian company, and a Guatemalan company, and gets paid by wire transfer to his bank account in Japan from his three clients... is he breaking the law in one or more countries? Perhaps there will be a telecommute country, with laws designed to let telecommuters live easily. Like incorporating in Delaware for companies.