Yesterday, as owner of an asset, I opened a support ticket and requested the cancellation of 2 sale orders for hundreds of thousands of tokens in promotion, whose terms of time to join had expired, because it was 4-5 days that you could not do it giving me the error “Something went wrong” and can’t do it by myself.
Nothing to say about the rapidity, they did it fast. 
The only thing I have to object to is the fact that nobody has bothered to verify that whoever put the orders was me. 
As issuer and trader I am very worried about this, I wonder what would happen if someone start asking to cancel the orders of others … could bring down the market prices of a currency, for example. 
Definitely, especially in cases of an asset issuer, which could require the cancellation of large amounts, I think it is necessary to always verify that it is the legitimate owner of that asset to request a cancellation, perhaps asking to send a symbolic amount of coins (ie 0.000001 ABC) from the waves address owning the asset attaching a message stating that you are the real owner. 
