In 2013, ProPublica released Prescriber Checkup, a database that detailed the prescribing habits of hundreds of thousands of doctors across the country.

ProPublica reporters used the data — which reflected prescriptions covered by Medicare’s massive drug program, known as part D — to uncover several important findings. The data showed doctors often prescribed narcotic painkillers and antipsychotic drugs in quantities that could be dangerous for their patients, many of whom were elderly. The reporters also found evidence that some doctors wrote far, far more prescriptions than their peers for expensive brand-name drugs for which there were cheaper generic alternatives. And we found instances of probable fraud that had gone undetected by the government.

The data proved equally useful for others: Doctors themselves turned to Prescriber Checkup to assess how they compared to their peers. Medical plan administrators and hospitals checked it to see whether their doctors were following best practices in treating patients. Law enforcement officials searched the database for leads on fraud and illicit trafficking in pain medications. Patients turned to the data to vet their doctors’ drug choices and compare them with others in their specialties.

Recently, though, we picked up clear signs that some readers are using the data for another purpose: To search for doctors likely to prescribe them some widely abused drugs, many of them opioids.

Like nearly everyone on the web, we use Google Analytics to collect data on our site. So far this year, it appears that perhaps as many as 25 percent of Prescriber Checkup’s page views involve narcotic painkillers, anti-anxiety medications, and amphetamines.

Thousands of the people visiting those pages initially viewed the “reporting recipe” we wrote to help local journalists identify doctors who ranked among the top prescribers of narcotics. The readership for this recipe far exceeds any reasonable estimate of local or regional journalists researching stories. According to our web data, many readers also arrived at Prescriber Checkup after web searches like “doctors who prescribe narcotics easily’’ or “doctors that will prescribe anything.’’

It’s not possible to draw definitive conclusions about the motives of these people. Some, no doubt, legitimately have chronic pain or anxiety and are simply looking for doctors who will help them. Two of the more frequently searched drugs are Suboxone and methadone, medicines used to treat opioid addiction. (As the depth of the opiod epidemic has become clear, some doctors have become reluctant to prescribe these drugs out of fears that they, too, can be abused.) Still, it seems probable that some of the readers who visit Prescriber Checkup are looking for doctors who will prescribe narcotics and other powerful stimulants with few or no questions asked.

This is not a new problem for journalists, or others whose business is providing or sharing information. In another era, burglars would read the obituary pages so they could target the homes of people who had just died. More recently, terrorists have used search engines to find recipes for bomb-making or encrypted communications. Con artists have found new ways to perpetrate schemes through Facebook and other social media.

The Internet’s leading platforms have struggled with this issue. Just this week, Google announced that it would not accept ads for payday lenders. Both Facebook and Google bar advertising for guns, explosives and recreational drugs.

We impose comparable limits on the advertising we are willing to accept on our site. But as a news organization dedicated to pursuing stories with “moral force,’’ we feel we also have an obligation to look hard at possible misuses of our journalism.

We have long been advocates for transparency and have repeatedly pushed government agencies to release more data on everything from dialysis clinics to complications in surgical procedures performed under Medicare. In almost every one of these instances, some government officials argued against making the information public, warning that the information would be misused.

Initially, when we published Prescriber Checkup, we had to request the data under the Freedom of Information Act. The government has come around to see the value of releasing prescribing information. Now, the Centers for Medicare and Medicaid Services puts the data freely on its own site. It even has a tool that allows people to compare doctors based on their opioid prescribing, just as our site does.

We continue to believe that Prescriber Checkup provides significant and beneficial insights into prescribing patterns — insights that can help patients, practitioners, regulators and a variety of other users. Doctors, the vast majority of whom want to do the right thing, have told us that this is the only place where they can measure their prescribing against colleagues in their specialty and state. And we regularly hear from law enforcement and medical board regulators across the country who say our tool helped them focus their efforts in ways that previously were not available.

Still, we recognize that it’s important not to ignore the not-so-beneficial uses of Prescriber Checkup. As one way of doing this, we are adding a warning to the pages of all narcotic drugs that reminds readers of the serious health risks posed by taking opioids for pain relief. We will also link to advice on their use by the Centers for Disease Control and Prevention and have written a story on the growing public health crisis arising from the abuse prescription pain medication. We will continue to report on this issue, as we’ve done previously.

Data journalism gives readers access to a stunning array of information on everything from healthcare to election results. As data sets grow ever larger, they also introduce ethical questions that journalists will be weighing for many years to come. We hope the actions we’ve taken contribute to that conversation