Instagram users are flooding the platform with black squares in support of black victims of police violence as part of a Blackout Tuesday protest. CNBC reports: As of 11:45 a.m. ET, more than 14.6 million Instagram posts used the hashtag #BlackoutTuesday. Searches for “blackout tuesday image” and “blackout image” surged 400% Tuesday morning, according to Google Trends. The idea of an…