[ryan_brunner]

A few bad apples were? Image based e-mail tracking is de rigeur to this day for nearly any marketing e-mail you receive, and has been since e-mail marketing has been a thing.

Any e-mail marketing provider worth their salt will include these without even asking the person sending the batch.

[yuhong]

So much that most email clients disable images by default and have been for years to help prevent abuse by spam.

[Jach]

And if it's actually important or you're curious or you can't read it and want to know what it says, you'll click the "show images" button. Email tracking is hardly a bad thing, it provides useful data. Some address never reading emails/never showing pictures? Stop sending them stuff.