Yes, well, in a lot of cases it is OUR OWN STUFF..!
Key US weapons that China stole (in particular)
Sikorsky UH-60 Black Hawk —> Z10, Z20
Humvee —> Dongfeng EQ2050
C-17 Globemaster —> Y-20
X-47B UCAV —> Lijian Sharp Sword
MQ-1 —> Chengdu Wing Loong “Pterodactyl”