Regarding horse meat, I really don't care. Between growing up in the Appalachia area, and traveling the world, I've ate worse sounding critters. People who cry about horse meat are the same ones who cry about venison, and for the same reason - IMO.
However, I don't like being deceived.
If your burgers have horse meat, just say so. Make it the #7 combo; Black Beauty Deluxe with Fries. Then people can choose.
And for what its worth, ABP Silvercrest also supplies meat to Tesco, Sainsbury, and several other markets. Tesco was also in the news this week.
Five Reasons Why Tesco's Horse Meat Scandal Could Happen Here - Forbes