The FBI has stepped up counterintelligence investigations of Chinese espionage in the U.S., reports the Washington Post this morning.

The paper reprises several recent cases, including, that of Chi Mak, convicted of stealing sensitive naval technology plans from a U.S defense contractor; Dongfan Chung, a Boeing engineer arrested in February, accused of funneling classified space shuttle and rocket documents to Chinese officials; Noshir Gowadia, indicted last fall for providing cruise-missile data to Chinese officials; and Gregg W. Bergersen, a Pentagon official who pleaded guilty this week to charges that he gave classified information on U.S. weapons sales to China.

What does this flurry of cases mean? A couple of non-mutually exclusive possibilities suggest themselves. One is that the Chinese are stepping up their collection efforts in the U.S. Another is that the FBI, in stepping up its counterintelligence and its work is bearing fruit. A third — a combination of the first and second — is that Chinese intelligence is not ten-feet tall.

That last possibility is suggested by some of the amateurish spycraft displayed by the Chinese in the Bergersen case. In one sense, the operation was fairly sophisticated. Bergersen was induced to take part in a false-flag operation, that is, an operation in which he believed he was selling secrets to a U.S. ally, Taiwan, when in fact the “businessman” he was dealing with, Tai Shen Kuo, was actually a spy from the mainland.

But there was also some remarkably sloppy behavior by the Chinese in this case. An elementary task of spying is maintaining covert communications. Kuo was eager to do so and he acquired PGP Desktop Home 9.5 for Windows, a commercially available program for encrypting emails. That was smart. It was not smart, on the other hand, to discuss this encryption software on an open phone line with his taskmaster in China. The FBI was listening in on the call.

The affidavit in support of the criminal complaint against Bergersen contains many other arresting details. One high point occurs when Bergersen returns from a trip to Bulgaria and his wife finds a wad of espionage cash in his wallet. Bergersen told her it was gambling winnings. Her reaction: she insisted on taking half of it “as her share.” Bergersen related this to Kuo who offered to make up the amount that he had lost to his spouse. This generous offer was declined.