I have written many letters to manufactures, stockists and organisations that endorse these companies regarding the danger of mesh bags.
I received the first response back from Gardman today. Below I have copied their reply.
"Many millions of fat balls and other bird food products in mesh bags are sold every year and the number of incidents is incredibly small. Gardman and it's advisors, the British Trust for Ornithology (BTO), believe that the benefits of feeding fat balls in mesh bags far outweigh the very small number of incidents each year. If consumers are concerned about the very small risk of birds becoming trapped they can easily be removed from the mesh bags and placed in specific feeders or fed loose on a bird table or the ground. We do have a statement on our products saying the fat balls are best fed from a feeder and that the nets should be disposed of as soon as empty. We have also started selling tubs of fat balls without the nets and if this is the way consumers wish to go we will increase how many we sell in this format. I can assure you that Gardman and the BTO are very concerned about bird welfare and all of the comments received from consumers are passed on so that they can be considered at our yearly range review meetings".