Rafael Palmeiro, the Baltimore Orioles star, told Congress that he had absolutely, positively never used steroids, but then he failed a urine test. So last week, he repeated his never-ever statement but inserted a new word: He never intentionally used them. He said: "I am sure you will ask how I tested positively for a banned substance. As I look back, I don't have a specific answer to give. I wasn't able to explain how the banned substance entered my body."

I can sympathize. A few years back, something quite similar happened to me. I got a ticket for speeding, and, being personally above reproach, I quickly deduced that someone had tinkered with my odometer and accelerator to create the impression that I was somehow to blame for exceeding the speed limit. Talk about unfair! Though understandably aggrieved, I paid the ticket. Later, I discovered that this happens to people all the time. While you're sound asleep, some unknown person comes and tinkers with your car, or if you're an athlete, with your personal bodily fluids. Understandably, many of the athletes are bewildered when this occurs, protesting innocence and shouting things like, "What? How many home runs did I hit last week? Why wasn't I told?"

It isn't just big stars like Barry Bonds and Palmeiro who are being victimized this way. It's also happening to obscure middle-relief pitchers with losing records. File it under "sports terrorism." Next, those skulking druggers will be gunning for innocent batboys, first-base coaches, and the guys who answer bullpen phones.

To their credit, some players who flunk their steroid test refuse to believe in secret nighttime visitors. Instead, after racking their brains for an answer, they conclude that somebody must have slipped them a contaminated Altoid. Or they announce that some apparently harmless diet supplement contained a steroid or an ingredient that mysteriously turned into a steroid in their body. "Evidently, I took a supplement of some sort that had a steroid derivative in it," Atlanta Falcons cornerback Ray Buchanan concluded a few years ago. Palmeiro's "never intentionally" explanation seemed to point the finger at supplements, though Associated Press reporter Alex Dominguez wrote that his "claims of ingesting steroids unintentionally were weakened by newspaper reports that the Orioles slugger tested positive for stanozolol, a powerful anabolic steroid not available in dietary supplements." Bonds explained that he took the now famous steroid products "the cream" and "the clear" in the belief that they were flaxseed oil and an arthritis rub. In 1999, Czech tennis player Petr Korda said he had no idea how the steroid nandrolene got into his system, though medical people told the news media that it could enter the body only through a large-bore needle. Some people probably believed that this finding tended to rule out the furtive nighttime drugging thesis, since a normally alert person like Korda might have noticed an intruder inserting an enormous needle into his body while he slumbered.

Lock up the Gatorade. Spiking the water or Gatorade of athletes is apparently another common way of inserting steroids into athletes without their consent. Canada's Ben Johnson offered this explanation when he failed his doping test after defeating U.S. athlete Carl Lewis in a famous race at the 1988 Olympics. Pole vaulter Janine Whitlock said something similar after testing positive for steroids at trials for the 2002 Commonwealth Games: "Of course I can't be 100 percent certain that anybody [spiked my drink], but I can't see any other way. You can't lock [drinks] away every time you take a vault, so it's possible." True enough. Locking up everyone's Gatorade bottle after each swig could sap the vitality of championship events.

One problem with the drink-spiking explanation, however, is that some victims, including Johnson, were found to have steroid levels associated with long-term use. Another difficulty is that athletes who ingest steroids by mistake often fail to notice that they then perform at amazing, if not superhuman, levels. At the 1988 Olympics, Johnson bolted out of the starting blocks with astounding force. Korda, though complaining of an ankle injury at Wimbledon, "went up for a smash," according to an opponent, "like he was Michael Jordan."

Ken Caminiti, the Houston Astros third baseman who died young from a drug overdose, estimated that at least half of the major-leaguers used steroids. Former major-league star Jose Canseco estimated it was 85 percent. But let's not get cynical. Most of the problem probably comes from those diet supplements, nighttime visitors, and all that spiked Gatorade.