1688 blacked out the buyer, and the other party didn't know. Put the other person on the blacklist, and the other person won't know. When the other party is blacklisted, no matter whether the application or the device is blacked out, it will not send a "blacked out" notice to the other party. Unless the other party guesses or verifies by sending a message, it will find that it has been hacked, but it has just been hacked and the other party cannot find it. 1688 is a B2B e-commerce platform in China, which belongs to Alibaba Group. The platform provides an online business trading market, mainly for suppliers in China and global buyers, and provides a platform for the wholesale, procurement and trading of various goods and services.