Azizi, posting a bunch of blank messages is the internet equivalent of sticking your fingers in your ears and singing loudly. It's passive-aggressive and serves to let the instigator know you read his message and had the desired reaction.

Not wasting your breath means not wasting your breath. It doesn't mean telling him "I read that and it bothered me so much that I'm not going to respond. Nope, you won't see me responding. Now, can you see that by posting this I'm not responding? I can not respond a bunch more times, too."