执法钓鱼，英美叫执法圈套，这是英美法系的专门概念，它和正当防卫等一样，都是当事人无罪免责的理由。从法理上分析，当事人原本没有违法意图，在执法人员的引诱之下，才从事了违法活动，国家当然不应该惩罚这种行为。行政执法中的“钓鱼执法”，与刑事侦查中的“诱惑侦查”，或者叫“诱惑取证”类似。世界各国执法机关也都使用类似手段，比如警察扮演瘾君子向毒贩购买毒品。但“诱捕”有着严格的控制要求，第一，诱捕对象是犯罪嫌疑人；第二，已经掌握其部分证据；第三，诱捕时的事实不作为犯罪证据。也就是说，所设之套本身，不能成为违法犯罪的证据。据悉，英美法系中专门有执法圈套（entrapment）概念，它和正当防卫等一样，都是当事人无罪免责的理由。大陆法系国家对此也有严格限制，日本法律禁止执法者为了取证，诱惑当事人产生违法意图，因为这是国家公权侵犯了当事人的人格自律权。

1. To determine whether entrapment has been established, a line must be drawn between the trap for the unwary innocent and the trap for the unwary criminal.
   判断钓鱼执法是否存在，必须分清陷阱是为无防备的无辜者设的还是为无防备的犯人设的。
2. Shanghai further probes entrapment controversy after alleged "black" driver cuts finger to prove clean.
   “黑车”嫌疑人自断手指以证清白，上海将进一步调查钓鱼执法事件。

A Shanghai company said yesterday that one of its drivers was entrapped by traffic authorities investigating illegal cabs, and it is threatening legal action if the case is not quashed.

Similar allegations have been raised by other drivers who claim the traffic watchdog, which is in the midst of a two-year crackdown that has generated millions of yuan in fines, used bounty hunters to manufacture false evidence.

In the latest incident, the driver was so disturbed about the allegation that he cut off part of a finger in a misguided attempt to prove his innocence. The Shanghai Traffic Law Enforcement Team for Pudong New Area has detained the company's vehicle and is investigating the case.

If the driver, Sun Zhongjie, who works for Shanghai Pangyuan Construction Machinery Engineering Co Ltd, is found guilty, Sun or the company will have to pay a fine of 10,000 yuan (US$1,465) to retrieve the confiscated minibus.

The company said Sun was innocent and claimed the 19-year-old was set up by the traffic team on a charge of operating an unlicensed cab after he picked up a pedestrian who asked for a lift.

"We think the team used entrapment," said Zhang Lili, an attorney for the firm. "Our company will take legal action if the enforcement team doesn't cancel the charge."

Charge denied

Authorities, however, denied any wrongdoing.

"The hitchhiker was not our man," Yan Liangming, deputy general commander of the traffic team, said in a TV interview. Yan also said the team had evidence to support its actions.

The conflict began at about 7:30pm on Wednesday. Sun was driving the company's minibus to a supermarket in Pudong and encountered a young man standing in the middle of his lane waving at him. The man, wearing a thin shirt, claimed to be cold and pleaded for a ride, Sun said.

Before Sun agreed, the man got into his vehicle and Sun drove on. After about a five-minute ride, the man jumped out of the minibus and left 10 yuan behind, Sun said. At about the same time, Sun was stopped by two minibuses from which several men emerged.

Sun said he was forced to sign a penalty notice admitting he was operating an illegal cab or they wouldn't let him go. They then drove off in his vehicle.

Saying he felt aggrieved, Sun went home and cut off the little finger of his left hand with a knife.

"I wanted to prove my innocence." Sun said, without specifying how the action would accomplish that goal.

Sun was then sent to an army hospital where his finger was reattached.

Bounty offered

Zhang Liwei, an official with Shanghai Traffic Law Enforcement General Team, told a local newspaper yesterday that none of the 15 district teams hired private agents to entrap drivers. But Zhang said that people who help catch illegal cabbies can receive bounties of 200 to 300 yuan.

Shanghai's Minhang District People's Court accepted a lawsuit a week ago by a driver against the district's Traffic Law Enforcement Team, which fined him 10,000 yuan for operating an unlicensed cab. The driver, Zhang Jun, alleged entrapment and said he was merely giving a ride to an apparently sick stranger.

Four months ago, a driver was allegedly entrapped by the law enforcement team in Baoshan District. He later sued the team but a court dismissed the case.

In 2008, a Minhang driver unsuccessfully sued traffic authorities twice over what he said were false charges of operating an unlicensed cab.

The same year, a woman was stabbed by an unlicensed taxi driver while she was working undercover for the taxi watchdog.

"These undercover investigators are supported by the teams and get money for catching black cabbies," a veteran licensed cab driver told China Youth Daily.