Z:gnu-www-ja-gpl-faq--5f5f9b-Because GPLv2 was written befo/en

Because GPLv2 was written before peer-to-peer distribution of software was common, it is difficult to meet its requirements when you share code this way. The best way to make sure you are in compliance when distributing GPLv2 object code on BitTorrent would be to include all the corresponding source in the same torrent, which is prohibitively expensive.