Finnish Coast Guard vessels surround the suspected Russian "shadow fleet" tanker Eagle S near the coast of Finland in January 2025.Jussi Nukari / Lehtikuva / AFPRussia is accused of using aging tankers to damage undersea cables.Analysts say it gives the cover of plausible deniability.But it's a method that also comes with risks.A series of apparent attacks on undersea internet cables show Russia exploiting a Western vulnerability, analysts say.The incidents in recent months involve aging tankers dragging their anchors and severing undersea cables in the Baltic Sea, prompting outages.The latest came on Christmas Day, when the tanker Eagle S dragged its anchor for hundreds of miles, damaged the Estlink 2 power line between Finland and Estonia and telecommunications cables.Officials in Europe say Russia is deliberately using the vessels to target the crucial infrastructure used to transmit internet data and power.They say the incidents add up to a campaign by Russia to sabotage infrastructure.