I dont think ive ever been anxious enough to do that . But i HAVE done that . several times . more from being absent minded though . <| sep |> You are making it sound like there was widespread theft , what the hell are talking about ? The only instance I could possibly think was they didn ' t have replay protection so one transaction could be broadcast across both networks , so in few incidents and I emphasize few , as this was not a common occurrence , some people may have lost some ETH or ETC by sending the money on one chain and not wanting to send it on the other . Further , it was easy enough to fix once it was known you could move the funds of one of them to a different wallet you control and thus no more chance of replay . This was an oversight in Ethereum forking which to their credit they didn ' t think the old chain would survive at all , and yes certainly is something that should be implemented in a hardfork to increase blocksize if it hasn ' t been already .