Uploading or downloading full episodes from the Internet Archive without permission is copyright infringement in most countries, including the US (under the Digital Millennium Copyright Act). However, the Internet Archive operates under the —meaning they remove content when rights holders file a takedown notice.
If you choose to download from the Archive, do so with full awareness of the legal and ethical gray area. Consider supporting the official release when possible—after all, continued support for English dubs ensures more series get localized in the future.
Use the Archive as a temporary backup or for archival research. For your annual rewatch of Lelouch’s epic chess matches and C.C.’s pizza cravings, subscribe to Crunchyroll or buy the Blu-ray. The dub’s brilliance deserves to be experienced in the highest quality—without fear of a DMCA takedown mid-episode.