There is one part of the right to object that everyone should be aware of.
The right to object always applies when your data is being used for direct marketing.
In other words, if someone is sending you marketing messages, and you tell them to stop using your data, they’ve always got to respect this.

This won’t work on illegal spammers, who by definition are criminals.
But if an organisation is sending you a newsletter that you don’t want, you’ve got every right to tell them to stop.