If you use a PUBLIC STOCK PHOTO SITE to purchase files for your cover, you have no right to stop other cover artists or authors from using a particular photo.
Exclusive rights to a photo are expensive. If you want an exclusive photo to use for you cover, you're going to pay out the nose.
Unless you're the photographer. Even then, you'll need permission if the subject of the photo is a person.
So, that means if you purchased the standard license, a non-exclusive licensing right from most of these stock sites, like ShutterStock, DepositPhoto, Adobe Stock, etc., you cannot stop someone else from using that photo if they buy the same standard license.
That also means you cannot harass other cover designers and authors. You're not going to succeed in shutting down everyone. And frankly, it makes you look like an uneducated idiot.
If you don't understand the different licensing rights, you probably shouldn't be submitting to publishers or publishing yourselves. You really need to learn the various licensing rights, or you may find yourself in a lot of legal trouble.
And no writer has time for that shit.
