Ukrainian artillery targets Russian soldiers by pinpointing their phone signals. Despite the deadly results, Russian troops keep defying a ban on cellphone use near the front.
Revelations that the cellphone of a top opposition politician was tapped have shaken the government and stoked concerns over just how widespread such surveillance is.
The wireless carrier said that it was working with the F.B.I. and the Secret Service to investigate a recent wave of fraudulent messages, but said the source did not appear to be Russian hackers.