It's intriguing. Klaus Gehrig, the Big Boss of parent company Schwarz Group, has indicated to the German media that Lidl is facing strong headwinds in America.The discount giant is working "flat out" to modify the store concept it launched in Virginia last June. Sales surfaces are to be reduced from around 2,000m² to 1,400m² and expansion slowed. Lidl's US stores are also likely to more strongly reflect the solid discount virtues which have led to success in 30-odd European countries.All this would be perfectly normal for a Plc that has already invested an estimated €2bn in a land where many top international retailers have come a cropper. It would be called giving guidance to shareholders. But Lidl is a privately-run company. So why has Herr Gehrig sounded the alarm bell?