The Federal Bureau of Investigation’s refusal to discuss even the broad strokes of some of its secret investigative methods, such as implanting malware and tracking cellphones with Stingrays, is backfiring — if the goal is to actually enforce the law.

In the most recent example, the FBI may be forced to drop its case against a Washington State school administrator charged with possessing child porn because it doesn’t want to tell the court or the defense how it got its evidence—even in the judge’s chambers.

The FBI reportedly used a bug in an older version of the free anonymity software Tor to insert malware on the computers of people who accessed a child-porn website it had seized. The malware gave agents the ability to see visitors’ real Internet addresses and track them down.

Defense lawyers for Jay Mochaud of Vancouver, Wash., argued they had the right to review the malware in order to pursue their argument that the government compromised the security of Mochaud’s computer, leading to the illicit material ending up there unintentionally.

An iPad Misplaced at the Airport Takes Its Own Vacation

Last month, Shelby Bonnie’s iPad vanished from his carry-on bag somewhere at Fort Lauderdale-Hollywood International Airport after a red-eye flight from San Francisco. He figured he would never see it again.But sometimes our devices aren’t ready to say goodbye.While Mr. Bonnie, an investment banker with Allen & Company, continued on his way to the Bahamas for a few days of relaxation, his iPad began a strange odyssey of its own, turning Mr. Bonnie into a digital gumshoe and the narrator of a personal thriller that played out on Facebook, to the delight of his online friends.“I said, ‘I’m definitely going to lose my iPad, but I’m going to have some fun,’” Mr. Bonnie said in a phone interview.

It is another mystery about the mysterious founder of Bitcoin.An Australian entrepreneur claimed on Monday to be the creator of the online currency. But almost immediately, digital currency developers expressed doubt about the claim.Craig Steven Wright, a computer entrepreneur, told the BBC, The Economist and GQ that he was the currency’s founder. He said he had been forced to come forward because so many people were pursuing him.“I didn’t take the decision lightly to make my identity public,” Mr. Wright said in a news release, “and I want to be clear that I’m doing this because I care so passionately about my work, and also to dispel any negative myths and fears about Bitcoin.”