It isn’t a good idea to talk to strangers. It’s usually an even worse idea to give your home address to them. Frank Warren, thankfully, didn’t take that advice and created PostSecret-the worldwide art project that has already accumulated more than 175,000 self-releasing pieces.

Warren created the artistic pop-culture phenomenon in November 2004, giving out 3,000 self-addressed postcards in Washington, D.C., and inviting people to send in their secrets.

Warren initially received only about 100 postcards back, but once the art project was published on the Internet two months later, he said that the idea “spread virally.”

That’s putting it lightly.

Now, three years after its birth, PostSecret brings in approximately 1,000 secrets each week. The project invites people to artistically share their deepest secrets with Warren-and, at times, the world.

Warren posts about 20 secrets a week on his website, postseceret.blogspot.com, and has produced four books, each of which include a personal secret of Warren’s hidden in the pages.

All secrets are delivered to Warren’s home in Germantown, Md., where he, his wife and their 13-year-old daughter sift through the decorative cards one by one.

“All families have family secrets,” Warren said. “[In my own family], there were some I never discovered, some I never got information about growing up . I believe that everyone has a secret that would break our heart … You could say that [PostSecret] is an exploration of my own secrets.”

With the number of postcards that Warren receives weekly, it is almost impossible to choose which postcards to feature, either in the blog or an upcoming book.

“I look for secrets that surprise me, secrets that are universal, secrets that are portrayed in a unique way,” Warren said. “I take experiences that are common, some that are funny, that involve sex, that are hopeful, that are tragic, and I turn them into a story.”

Warren’s fourth book, A Lifetime of Secrets (Oct. 9, HarperCollins), chronicles human life from ages 8 through 80.

“It shows how some secrets change over time, yet some remain exactly the same no matter how old they are,” Warren said.

In addition to his four books, five blogger awards and a mention on Forbes list of “the 25 biggest, brightest and most influential people on the Internet,” Warren has also traveled the country speaking about his experiences with the art project. His most recent tour centered around working with college-aged people, as he said that “the project really resonate[s] with young people.”

In addition to reaching out to students, Warren is affiliated with Hopeline, a suicide-prevention hotline (1-800-SUICIDE). Warren was involved with the organization before PostSecret came about after he lost a friend and a family member to suicide. The organization is still close to his heart and is mentioned on the website after new posts.

“I do receive emails that have been helped by the hotline or after seeing their secret published, which acted as a release,” Warren said.

Despite the success that Warren has had, he initially had reservations going into the project.

“Using my home address does kind of make me vulnerable,” Warren said. “But a stranger might feel more comfortable sending a postcard to my house . then we’re both vulnerable.”

Warren has not had problems in the past, but has had a few visitors, simply reasoning that “people are curious.”

Though he doesn’t have a specific favorite secret, the first book featured one that stuck out in Warren’s mind.

“It was on a Starbucks cup, and it said, ‘I give decaf to customers who are rude to me.’ I think about it every time I get coffee,” Warren said. “Always be nice to your baristas!”

As for the future of PostSecret, Warren tries not to impose goals on the project.

“I trust the journey, and I’ll continue to follow where it leads,” Warren said. “I guess my secret is that I hope the postcards never stop coming.”