Eurovision 2015 organizers were prepared this week to use "anti-booing" technology if the audience heckled Russia's contestant. Coordinators for the annual international song competition told the Moscow Times that they'd installed sound reducers in case the crowd turns ugly after Polina Gagarina's performance. The new measure was a response to the 2014 contest, when Russia's Tolmachevy Twins were booed on stage for their nation's role in the ongoing Ukraine conflict, the Daily Mail reported.
International Business Times: Eurovision 2015 – amid Ukraine conflict

Polina Gagarina from Russia performs during a dress rehearsal for the first semi-final of the Eurovision Song Contest (ESC) on May 18, 2015 in Vienna.