Imagine being able to run an instant background check on a blind date, job applicant or new neighbor — all with a few taps on your smart phone.

Sounds convenient, right? Not if you’re a victim of stalking or identity theft, share the same name as a registered sex offender, or just cherish a certain degree of privacy.

That’s the idea behind BeenVerified’s mobile app, which scours public records and the web for all kinds of information about people — from past convictions to what kind of music and books they like. The popular iPhone tool, launched in 2009 by two Marlboro High School graduates, was downloaded nearly 1 million times before Apple pulled it amid growing concerns about privacy invasion.

Now, two years later, the Manhattan-based startup has relaunched the app — this time for both iPhones and Android devices — with the aim of making background checks accessible to everyone, not just private investigators. The tool, which was initially marketed as a service for employers, provides users with a quick way to confirm identities in a new era of online social networking where people are "meeting" on Craigslist, Match.com and Facebook.

"All these anonymous interactions are leading people to say they need to trust but verify," said CEO Josh Levy, 31. "We’re seeing hundreds of thousands of searches each day, so clearly there’s a demand in the consumer market."

Here’s how the app works: For $2, it searches for a person’s phone number, address, names of relatives, criminal records and property records. For another $2, the app conducts an email search, which finds social media profiles, Amazon.com reading lists and Pandora radio playlists. For $20, BeenVerified’s website offers an even more comprehensive check, covering bankruptcies, sex offenses, judgments and liens.

A few caveats: Not everyone is searchable to the same degree. People who recently lived abroad, for instance, might not show up. The checks can’t access private profiles on Facebook, LinkedIn or other social media sites. When necessary, as with court records, the company pays for the data.

Levy, 31, and co-founder Ross Cohen, 30, insist the app is entirely legal because it draws only from public records.

But cyber security experts and privacy advocates say BeenVerified is just one of many "information brokers" that are pushing the blurry boundaries of privacy in a new digital age.

Social Intelligence, a startup that provides employers with background checks on a job candidate’s internet and social media activity, also attracted scrutiny when it launched last year. The Federal Trade Commission started an investigation but dropped it in June after determining the company was compliant with the Fair Credit Reporting Act.

While background check services offer the public some advantages, there is a high risk for abuse, such as stalking or identity theft, said Gary Kessler, a cyber security expert in Burlington, Va.

"We’re hiding under the banner of ‘this is my right to know,’ but it’s merely a way for someone to sell a service to people who are just nosy or curious," Kessler said. "We need to figure out whether the tradeoffs are worth it."

Even basic personal information can be used in dangerous ways, experts say. In a 2009 study by Carnegie Mellon University, researchers discovered that simply knowing a person’s place and date of birth was, in many cases, enough to determine their Social Security number.

"There are deep implications for privacy even if it’s not certain these tools violate the law," said Rainey Reitman, activism director at the Electronic Frontier Foundation, a nonprofit advocacy group focused on how technology affects free speech and privacy.

For people with an "acute need" for privacy, such as stalking victims, judges, public defenders, and people who are entangled in divorces or child custody battles, background checking tools unfairly put them at risk, Reitman said. In some cases, when public records are wrong, these tools also spread those inaccuracies more quickly, she added.

"They’re just putting it in an app store and hoping a million people download it, without taking into account consumers’ risks and rights," she said.

But BeenVerified’s Levy disagrees. What the app does, he said, is simply modernize information databases that already exist. For instance, the company is in the process of downloading criminal records from 3,100 counties, he said.

"In the old days, you used to send in all the info to the courthouse in the county you lived in," he said. "We’re providing a service that’s definitely needed, and people are looking for."

Leslie Kwoh: (973) 392-4147 or lkwoh@starledger.com.