Here's an old post I made on the subject,
If you ever dare to even think of doing such a thing, you will be promptly reported by an extensive network of informants and whistleblowers, among others, to the FBI, the CIA, the NSA, the IRS, the Delta Force, the NAVY Seals, the USMC, the KKK, the Stasi, the Gestapo, the MI6, the KGB, the NKVD, the Sigrimi, the Securitate, the Khmer Rouge, the NKPA, the Simon Wiesenthal Institute, the Mossad and the Tonton Macoute.
I'm talking about the actual commercial Doom wads, ie. DOOM.WAD, DOOM2.WAD etc. so I'm not sure if it is legal to even put those on flash drives to put in other computers, whether or not he takes it off and puts it on his computer.