[Digital-Citizen]

The X11 license (MIT has used multiple licenses so there is no single "MIT license") does say "The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software." but not doing so is not theft.

The grandparent poster is correct -- copyright infringement is not theft and the two ought not be conflated. https://www.gnu.org/philosophy/words-to-avoid.html#Theft explains why: "Under the US legal system, copyright infringement is not theft. Laws about theft are not applicable to copyright infringement (http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=us&vo...). The supporters of repressive copyright are making an appeal to authority—and misrepresenting what authority says.".

The GNU Project also recommends pointing people who misuse the word "theft" in this way to https://www.theguardian.com/books/2013/may/04/harper-lee-kil... -- "which shows what can properly be described as 'copyright theft.'".

Please don't join people in getting this wrong. Even some of the most hostile abusers of that conflation have recanted (the MPAA was denied use of that conflation per https://torrentfreak.com/mpaa-banned-from-using-piracy-and-t... and the MPAA's Chris Dodd admitted that conflation was wrong according to https://torrentfreak.com/mpaa-piracy-is-not-theft-after-all-...).

The copyright holder in this case has options including suing, but calling what happened as "theft" is not an option and is unlikely to get anywhere with a judge.