Some LinkedIn users have reported receiving unsolicited flirtatious messages via the platform, with expert Bernie Hogan at the Oxford Internet Institute saying the employment-focused social website is increasingly being used for dating purposes.

Blair Huddy, founder and CEO at Hudson Davis Communications, told CNBC that one LinkedIn user sent her messages on two separate occasions asking if he could connect her with clients for her business, to which Huddy didn't reply.

"Shoot me a text back whenever you're done playing hard to get," the user said in a final message, which was viewed by CNBC Make It via screenshots.

Huddy, a Los Angeles-based 35-year-old, said she often screenshots messages like this and posts them on LinkedIn with a direct tag of the person who sent the messages.

"It's just a gross feeling ... it's gross, it's unprofessional," Huddy told CNBC. She's been an active LinkedIn user since 2012.

Shriya Boppana, a technology consultant, also reported receiving uncomfortable messages on the platform. She attracted the attention of "a really odd group of followers" back in 2020, she said, after updating her LinkedIn profile to reflect that she had recently won a beauty pageant and had secured a hosting gig on a TV show.

An IT support worker, with whom she had previously worked with, found her on the platform and told her she looked "pretty," according to messages reviewed by CNBC. Another man sent her a message, seen by CNBC, which said: "I have always known you were beautiful but you never told me you were a pageant queen." Both Huddy and Boppana are still active and posting on LinkedIn.

A LinkedIn spokesperson told CNBC Make It that the platform — which was launched in 2003 and now has more than 1 billion members globally — defines itself as a "professional community," adding that it encourages members to "engage in meaningful, authentic conversations." LinkedIn is owned by Microsoft.

"This includes light-hearted, respectful conversations, as long as it does not violate our community policies. Romantic advances and harassment of any form is a violation of our rules, and our policies include detailed examples that show what kind of content does not belong on LinkedIn," the spokesperson said.

Solid data on the issue is scarce. According to a survey last year of 1,049 female LinkedIn users in the U.S., some 91% said they had received romantic advances or inappropriate messages at least once on the platform. Seventy-four percent of respondents felt the need to disengage or limit their activity on the platform as a result, according to the survey published by photo studio Passport Photo Online.

Looking more broadly at user activity, another more recent survey of 505 U.S. consumers between the ages of 20 to 40, published by DatingNews.com, found that 52% had met people for dating via networking platforms like LinkedIn and Facebook.

'Not a workplace'

Bernie Hogan, an associate professor at the Oxford Internet Institute, told CNBC that LinkedIn is a social media platform, just like Instagram or Facebook. Although using LinkedIn is often "framed as a work activity," users are free to send any kind of message to whoever they want without strict regulations, Hogan said.

"LinkedIn is not a workplace, it merely frames itself as a workplace," he told CNBC Make It. "Offices, and workplaces, would normally regulate this sort of thing but social media leaves it to people to regulate."

Hogan said he thinks that LinkedIn doesn't appropriately sanction users for inappropriate behavior, and this often leaves the victim to deal with it on their own, using strategies such as blocking or public shaming.

"LinkedIn has to absorb some of the responsibility of maintaining a professional environment because they can't offload this to people's employers," he noted. "Their employers don't run LinkedIn."

The LinkedIn spokesperson highlighted that the platform already has advanced safety features to protect users from unwanted behavior. The feature "when enabled, warns members when harassment is detected within private messaging," the spokesperson said.

"We also encourage members to report any instances of harassment on LinkedIn and signal to us that such behavior is unwanted, allowing us to take action," they said.

These actions can be removing the content that the offender sent or even suspending their account.

But Hogan suggested LinkedIn should start incorporating AI tools to keep users who are sending inappropriate messages in check, rather than putting the onus on the person receiving the messages to report or block the perpetrator.

This would mean users who try to write inappropriate messages would be detected by AI and either warned or prevented from sending the message at all.

"We already have online dating sites where people can't send overly aggressive messages. Bumble and Tinder have safety protocols already so people can't send unsolicited pictures or sexualized pictures. They can inhibit that. LinkedIn should also have such technology at their disposal," Hogan added.

Courtney Boyer, a relationships expert, told CNBC Make It that LinkedIn is becoming an alternative to traditional dating apps like Hinge, Tinder, and Bumble, which have fallen out of favor.

A recent Forbes Health Survey of 1,000 Americans who have used dating apps in the past year found that 78% felt fatigued emotionally, mentally, or physically by dating apps sometimes, often, or always.

"People are jaded by traditional dating apps because they don't have those easily filtered things that people value," Boyer explained, saying that users have to pay more to access certain filters on some dating sites.  

However, on LinkedIn, you can easily filter people by their sector, education, and experience level for free which are all features that can add to one's "sex appeal" while dating, Boyer added.

Hogan at the Oxford Internet Institute agrees, saying the nature of the site is "adjacent to dating" because it involves "the practice of presenting the self to meet people you don't know for some end."

"So LinkedIn has effectively created a dating site without dating," Hogan added.

Central Florida-based Sasha Dutta, founder and CEO of wedding planning company Fierce Events, said she has received her fair share of flirtatious DMs on LinkedIn. However, she added that she would have considered some of the more respectful messages if she wasn't in a relationship at the time.

Thirty-four-year-old Dutta, who is South Asian and now married, says her community values career and education compatibility highly when two people get together romantically.

"I don't see it as a bad thing ... the proliferation of dating apps has just been enormous and every friend I have that's on a dating app says it's like a part-time job and a lot of work just to weed through everybody," Dutta explained.

"I think with LinkedIn, you just cut out a lot of the things you would ask them on the first date, like what do they do or what is their career trajectory, very basic surface-level questions, you get that right out of the way."

LinkedIn's professional community policies state: "LinkedIn is a professional networking platform, not a dating site. Do not use LinkedIn to pursue romantic connections, ask for romantic dates, or provide sexual commentary on someone's appearance or perceived attractiveness."

Behaviors shifting online?

Huddy, who met her husband when they started working together, says millions of people met their partners at work in real life.

"A lot of the activities that we were doing at work in person are shifting to online behavior," she said.

She said it's not necessarily a bad thing to approach someone on LinkedIn, "you just have to be careful how you do it," Huddy said.

The most important factor is allowing others the freedom to say no and exit a conversation if they're not interested, the Oxford Internet Institute's Hogan added.