Z:gnu-www-ja-gpl-2.0-faq--801ebc-You're supposed to provide the/en

You're supposed to provide the source code by mail-order on a physical medium, if someone orders it. You are welcome to offer people a way to copy the corresponding source code by FTP, in addition to the mail-order option, but FTP access to the source is not sufficient to satisfy section 3 of the GPL.