Most would agree that knowingly infecting others with HIV is criminal. But what if someone is unaware of his or her HIV status and transmits the disease? Should this too be punishable by law?

Let’s muddy the waters a bit. Say the virus is transmitted by someone who frequently engages in high-risk sexual behavior and may have reason to believe he or she is infected, but engages in unprotected sex anyway and infects another person(s). Is this a negligent act? California’s highest court seems to think so.

On Monday, the California Supreme Court ruled that people who have good reason to believe they may be infected with HIV are responsible for informing their partners about possible exposure. According to The Associated Press, the court’s 4-3 ruling makes those with “constructive knowledge” – people who should have known by their behavior and other signs they were infected but didn’t – legally liable for infecting others.

Getting caught up in the language? Yeah, we are too. For example, what is considered “constructive knowledge” of high-risk sexual behavior, and how does the court determine if someone should know they may potentially be a carrier of the disease?

Knee-jerk reaction: This is outrageous! But if you examine the case before the court in detail, it’s hard not to agree, at least in part, with its ruling.

The case involves former spouses Bridget B., the plaintiff, and John B., the defendant. The couple met in September 1998 and began dating shortly thereafter. They became engaged in late 1999 and were married in July 2000.

During this period, John presented himself as healthy, disease-free and monogamous, and the couple began having unprotected sex. In September 2000, however, Bridget began suffering from exhaustion and high fevers, and that October she tested positive for HIV. John was tested and he too was positive.

Bridget alleges that John later admitted to having sexual relations with men before and during their marriage, and used the Internet to solicit these relationships. The claim further alleges that John knew he was positive, or had good reason to know he was positive, prior to their marriage.

John denies these claims and says he tested negative for HIV in August 2000 in connection with a life insurance application. He says he did not discover he was HIV positive until Oct. 13, 2000, and that it was Bridget who infected him with HIV.

For argument sake, let’s say Bridget is correct and John infected her with the HIV virus. Is he responsible even if he was unaware he was HIV positive?

Absolutely. If Bridget indeed had no knowledge of John’s sexual relationships with men prior to and throughout their marriage, she was robbed of any opportunity to make informed decisions in regard to her own sexual practices to avoid the risk of infection.

Once a couple makes the decision to be in a monogamous relationship and practice unsafe sex, whoever deviates from that decision and fails to inform the other partner about potential risks should be held liable if their actions cause physical harm to their partner.

It’s the implications of this ruling that have us worried, however.

“One can easily foresee a spate of ‘shakedown’ or vengeance lawsuits brought by plaintiffs whose motivation is not so much to discover how they contracted HIV as to force lucrative settlements or embarrass a former sexual partner by exposing that person’s sexual history in the guise of obtaining relevant discovery,” Justice Carlos Moreno wrote in dissent.

And that’s really the issue, isn’t it? How will this universal ruling be applied or, perhaps more accurately, abused?

Each and every one of us has the responsibility to protect ourselves. However, at what point do we put our lives in the hands of the people we love? If we must draw a line in the sand, as this case suggests, once we disclose our medical and sexual histories and enter into a verbal contract, such as monogamy, both partners become responsible for one another’s well-being. If either partner strays, as will happen in some cases, that partner has the responsibility to inform the other of that indiscretion so that he or she can make an informed, autonomous decision regarding their own sexual health and well-being.

Our society doesn’t flinch at suing friends and lovers over car accidents and other personal injury cases. Is HIV so different?