A worker pauses while preparing the Google stand the day before the CeBIT 2012 technology trade fair officially opens to the public on March 5, 2012 in Hanover, Germany. Sean Gallup | Getty Images

When John Lewis heard that Google+ was shutting down after the discovery of a security bug that left private profile data exposed, it felt like a crushing blow — even though he could see it coming. Lewis, a freelance writer who has spent nearly eight years living an isolated life in the Costa Rican rainforest, starts almost every morning sipping coffee while chatting with friends on Google+ and reading his feeds on the social network. "Plus has long been Google's orphan child," Lewis told CNBC by phone on Monday after Google announced that it's shuttering the 7-year-old service in the coming months. "I had hoped that it would stay that way forever." Lewis is among a tiny but fiercely loyal cadre of Google+ users who stuck with the site for years, undeterred even as Google carved it into pieces or outsiders declared it dead. It had become so irrelevant as a landing spot that, by Google's own admission, 90 percent of user sessions lasted less than five seconds. But for people like Lewis, that was all part of the charm. Unlike Facebook, which has thrived by getting billions of users to share baby photos alongside ads for shoes, and Twitter, where bullies and bots have proliferated, Google+ has remained a quiet social enclave where users say they're able to engage in meaningful conversations and get useful feedback. Most notably, Google+ fans say the site's lack of ads, the ability to write long posts, and a focus on topics to connect people — instead of existing friendships or public figures — created a platform that encouraged real, sustained dialogue with strangers. "It's really been a lifeline for me," said Lewis, who created a group called "Google+ Mass Migration" in the hopes of salvaging his adopted community. "The social interactions I'd have there I couldn't get anywhere else."

Here's a look at the "Google+ Mass Migration" group

Since Lewis started the group on Monday, it has gained more than 1,500 members who are using it as a place to vent, mourn, publish fond memories and suggest alternatives for when the site disappears. Meanwhile, a Change.org petition begging Google not to shut Plus down at all has over 18,000 signatures. It's all become a form of collective therapy following the company's decision on Monday to close Google+ after a security hole highlighted the challenge of keeping its small number of users safe. Edward Morbius, one member of Lewis' group, told CNBC by e-mail that he's met people from all walks of life on Google+, including some he considers his closest confidantes, even though they've only communicated online. Morbius, who doesn't use his real name on the site and appreciates that Google allows him to remain anonymous, said there's a depth to conversations on Google+ that you can't find on other social sites. "There are discussions which could extend over days, or weeks or months, even years, and do so productively," Morbius said.

A eulogy for Plus

That small fan base came together despite Google's recent negligence. After Google launched Plus in 2011, it quickly became known as a wannabe-rival to Facebook. At first, Google poured resources into the service, even forcing people to use Google+ as a way to connect and sign onto other services like YouTube, Calendar and Gmail. But unable to gain traction against Facebook, Google began to walk back its efforts. Vic Gundotra, who ran the product in its early days and was its chief evangelist, left in August 2014, after eight years at the company. The next year, it broke the product into parts and stopped requiring users to tie their Google+ profile to other services. After that, if you weren't a Google employee, odds are you didn't have an active profile on Google+. Peter Vogel was in the dedicated minority. Vogel, a physics teacher in Vancouver, Canada, has almost never skipped a day posting on the platform. He calls Plus a "learning environment" and said his posts about space, astronomy and cybersecurity elicit intelligent and thoughtful commentary. Similarly, Hans Franke, a longtime German user, said he still spends at least an hour a day actively posting and reading, and loves the diversity of smart, "unusual" people with whom he converses. As they and others in Lewis' group look for places to go when Google+ disappears, some have recommended smaller platforms like Mastodon and MeWe. Plus users have also been swarming to Pluspora, a community built through the Diaspora Foundation that was started about a month ago by a handful of people who feared that Google would eventually kill their favorite site. Diane Cleverley, a co-founder of Pluspora and a medical writer, said Plus filled a gap in her social life and created something that feels like an extended family. She's met artists and scientists and hosted internet friends in real life. Cleverley is grateful that she had the foresight to create Pluspora but is upset about the way Google is abandoning its users. Lewis shares that disappointment.

Harsh goodbye