I only use them for webmail (a service that barely works) and I'm not happy about this. My only remedy if I don't like this, according to their rather glib help page, is to delete my Yahoo account. There is no option to avoid them hawking my personal details (presumably gleaned from e-mails) around 50 other companies. GDPR is really going to have teeth, isn't it?
I know they're one of the most mismanaged companies in the world but this takes the biscuit. It will be laborious, but I might just bother to change my e-mail address. I suppose this applies to Flickr too (another service that barely works).
Can anyone suggest what the "oath" is?