The Russian “shadow fleet” raises Germany’s fears.. What is the story?

Following damage to an undersea power cable off Finland, German Foreign Minister Annalena Baerbock sounded the alarm over Russia’s so-called shadow fleet, calling for further EU sanctions.
Baerbock said in statements to the newspapers of the German “Funke” media group published on Saturday: “Almost every month, ships currently cause damage to important submarine cables in the Baltic Sea.

“Ship crews lower anchors into the water, drag them for several kilometers across the seabed for no apparent reason and then lose them when they pull them out,” she said, adding that she finds it difficult to believe that these incidents are mere coincidences.
The Minister warned: “This is an urgent wake-up call for all of us. In a digital world, submarine cables are the communications arteries that connect our world together,” stressing the need to strengthen the protection of vital infrastructure.
The Estlink 2 cable between Estonia and Finland was cut last Wednesday, and the Finnish authorities suspect that it may be an act of sabotage, and accordingly detained the Cook Islands-flagged oil tanker “Eagle S” after suspecting that its anchor had caused damage to the cable.