There's only one way to deal with spam. Ignore it.
Perhaps you have something more interesting to do with your time.
I don't think it's a good idea just to ignore it. this spam may cause some problem to people that is not aware of it.
Correct, this is spam, and how do we deal with email spam? With filters in order to reduce the noise, spam filters have become so effective that only one out of 1000 reaches its destination. So there could be a way to implement something similar in the Bitcoin Core?