Using USB-VGA dongles as SDR transmitter
That's a neat party trick and all but abusing spurious emissions/harmonics to broadcast in licensed spectrum without proper filtering is just plain irresponsible. At low power, with an unmatched antenna those signals /<i>probably</i>/ won't make it out of your house but it's not good practice to spew harmonics all over the spectrum, especially GSM bands. I also can't believe that they are working on increasing the TX power. Purposefully emitting all over the spectrum is both iresponsible and illegal.