The perpetrators stay anonymous, making it impossible to trace the forgery back to its origins.
Then, even more mysteriously, he dismantled the taps making it impossible to trace the eavesdroppers.
Not all currently do so, making it impossible to trace such promises back to the municipalities that have to pay them.
But in what some officials described as a possible blunder, the officials said no effort had been made to keep track of the informer, making it impossible to trace whoever provided the tape.
The gun's serial number was scratched off, making it impossible to trace, spokesman Jim Amormino said.
A VPN router gives all devices connected to the network a new, anonymized IP address, making it impossible to trace their online activity back to your home.
Furthermore, even the previous exchanges of fish between laboratories were not recorded in a pedigree format, making it impossible to trace the origin of the genetic variability that we now observe.
In the past, complete anonymization of samples, making it impossible to trace back the identity of the original donor of the sample, has been recommended to avoid problems related to certain of these issues.
