Russian Navy vs Somalian pirates

This is why Somalian pirates avoid Russian ships.

On 5–6 May 2010 Somali Pirates hijacked the Moscow University, a Liberian-flagged Russian tanker, in the Gulf of Aden. Her crew was freed by the Russian Navy destroyer Marshal Shaposhnikov the following day.
After arresting and removing the pirates from their vessel, the sailors destroy the boats with an AK-630 close-in weapon system (CIWS) based on a six-barreled 30 mm rotary cannon.