Nearly 150 tech companies (including us via the Copia Institute), non-profits and computer security experts have all teamed up to send a letter to President Obama telling him to stop these stupid ideas about backdooring encryption that keeping coming out of his administration. The press headlines will note that big companies — like Google, Apple, Cisco, Microsoft, Twitter and Facebook — are signing the letter. But significantly more interesting is the signatures from a huge list of computer security experts, all putting their names down on paper to make it clear what a ridiculously bad idea it is to even think about backdooring encryption.