ad-blocking ethics
Indeed it is ethical for me to block unsolicited advertisements from appearing on the web pages I visit.
I do not wish to see them. Moreover, I have made a promise to myself NEVER to buy a product or service that I see in an unsolicited web advertisement.
Therefore,
1. ad-blocking is beneficial to me, because I do not wish to see them.
2. ad-blocking is beneficial to advertisers, since it is possible for me to buy their product or service only if I do not see their advertisement.
Everybody benefits.
Biting the hand that feeds IT
