Russia has a lot of these. I think Greece has a huge fleet of tankers, likely legit.
I understand there is a lot of on the seas oil transfers.
I recall there was a Norwegian NATO frigate that had turned off its location transponder and had entered a busy fjord. It hit an oil tanker and sank. I recall listening to the audio. The frigate showed up on radar and people were yelling over the radio to no avail.
The people responsible were not named, maybe because they were women.