Kickstarter project aiming to clone the MakerBot is legal, but does that make it right?

Matt Strong invented a 3-D printer called TangiBot. More precisely, he built an exact replica of the MakerBot Replicator and is attempting to raise $500,000 on Kickstarter to fund its production.

In most cases, he would be met with a swift cease-and-desist letter, but the MakerBot Replicator is open source, meaning anyone can copy it and sell it. While legal, the TangiBot has raised the ethical hackles of many in the maker community.