Beijing: An estimated 100 billion spam messages harassed China's one billion mobile phone users in the past year, a study said.
Of them, more than 10 billion were intercepted by a security software for around 70 million users, the China Daily reported.
On an average, cell phone users receive 11 unwanted messages each week, according to a survey by the Internet Society of China.
Fraudulent messages top the list. Around 65 percent of mobile phone users last year received false messages saying they had won a prize, 47 percent received messages about fake bills and 46 percent received messages pretending to be from their bank.