LAKELAND, Fla. (WTSP) -- A new craze is taking over Lakeland, and anyone can do it. You paint a rock, add the message "Lakeland Rocks" on the back and hide it for a stranger to find.

A Facebook page for Lakeland Rocks has more than 20,000 members in just a few weeks.

“We’re so humbled that the community has actually rallied behind us,” said Scott Urqhart, who started the group after seeing a similar one on a vacation in Washington.

He said he started it to spread positivity, but with a group this big come some problems.

The city said people have disrupted a wedding party at Hollis Garden looking for rocks. Some rocks have gotten caught in lawnmowers. Most recently, a well-meaning vandal painted a "rock drop off" at a public park.

“Even though it wasn't done maliciously, it's still something that we need to address,” said Kevin Cook, communication director for the city.

The city already cleaned up the paint at the park, and now Urqhart is doing the best he can to make sure problems like these don't happen again.

“We don't condone it. We don't want them to do it,” he explained. “It's not part of the message our group is trying to spread.”

Urqhart and the city both hope people can just get back to showing everyone how much "Lakeland Rocks."

“Be respectful and be mindful and treat other people as you'd like to be treated and it's all good,” Cook said.

Urqhart said he posted some ground rules on Facebook, which he hopes every group member follows.