If you pay for Yahoo! mail you don’t get ads. Why do you think you are entitled to something for nothing? Either accept the ads (which pay for the service) or pay for the service.
Im sure it was going on but now they are boldly declaring it to the world that they will scan emails...
You make it sound like people who object are automatically part of the ‘something for nothing’ crowd. Prior to the update Yahoo mail did not attempt to cover costs/generate revenue through email scanning or outright charging a fee.
After having relative email privacy from the beginning (to the knowledge of the user), suddenly having private communications scanned simply does not sit well, especially with the recent gov’t snooping on every American everywhere (execpt for muslims).
I don't mind the ads - they are an appropriate way to pay for the "free" service. I do mind the scanning. It's creepy and inappropriate. I will not deal with providers that scan my private communications - that's for tyrants like Obama, who have overwhelming force, not for companies that I freely choose to deal with.