Horse and pig dna found in UK beefburgers

Or why it's a good idea to have regulations.
Beefburgers sold in some of the biggest supermarket chains in the UK were found to contain horse and pig DNA.
http://www.bbc.co.uk/news/uk-21059623
Beefburgers sold in some of the biggest supermarket chains in the UK were found to contain horse and pig DNA.
http://www.bbc.co.uk/news/uk-21059623