Flickr has teamed up with Pixsy to help protect images on Flickr. Pixsy is a service that will scan your photos. then using reverse image search and some Ai as well will periodically review and report on any other locations around the web your image is being used. Some are legit but other can require take down notices and possibly seeking damages or payment for licencing images (these are more legally complex and really focussed on US based copyright registration).BTW pixsy does get paid unless you do.
I think something like this is well overdue and will add some teeth to Flickr’s licencing (its the only social media outlet I know that still display the licencing details with the detail photo display). There are still creative commons options as well as full copyright. Importantly Pixsy can send legally binding takedown notices.
If you are new to flickr you might find it wise to turn off the download options to discourage “inadvertent steeling” of your photos . Alternatively you may also wish to change your privacy for Friends &/or Family.
This Pixsy service is only being offered to FlickrPro subscribers, and really does value add if you want to use flickr as a place to share your work to a wider audience but are worried about image theft. I’m going to stay with my free account because I already signed up to a free versions of pixsy monitoring connected to my flickr account quite a while ago and you can still independently do this but there are limits.