Thanks for the tweet, Mayor Kenney, but the Great Rittenhouse Square No-Sitting Controversy is far from over.

For those of you who managed to stay away from your social-media feeds last  weekend, Philadelphia's mayor took to Twitter on Saturday night to reverse his administration's new ban on the time-honored practice of parking your bottom atop Rittenhouse Square's elegant limestone balustrades. The tweet was a response to the mounting outrage over the ban's exclusionary implications, and to plans for a "Sittenhouse Lunchtime Sit-on" on Tuesday. "This government is very large and at times things just get by you," an apologetic Kenney wrote. "Sit where you want."

There is something wonderful about having a mayor who can be so self-effacing and responsive, and he immediately received an outpouring of praise for the message. He later tapped out another tweet promising to deal with the details later this week. Yet, as the country is quickly learning, Twitter statements are not the same as policy-making.

Two days after his declaration, a stack of issues remain unresolved: The offensive (and seriously twee) signs, which bear the logo of the city's Parks and Recreation department, remain in place next to the balustrades that encircle the square's central court. The park's security guards must not be Twitter users because they were apparently unaware of the mayor's decree as late as Sunday, according to several people who attempted to take to the walls.

We've also heard nothing about the obnoxious police cruiser that has been parked in the square, running its engine and spewing exhaust -- a violation of park rules, incidentally --  pretty much nonstop since October's drug-related shooting.  If the problem with the no-sitting signs is that they make the park seem unwelcoming, the cruisers practically exude a police-state sensibility.

So, though  the mayor's tweet was a crowd-pleaser, it addresses only the most superficial aspect of the larger problem: the city's increasing reliance on a private partner to manage and fund this most beloved and democratic of Philadelphia public spaces. Even though Rittenhouse Square is in the toniest part of town, there is a strong sense that these gracious seven acres belong to all of us. It's common ground.

Yet, after the Billy Penn website broke the news of the ban last week, that private group, the Friends of Rittenhouse Square, issued a statement that seemed to express more pique than penitence. Because the group raised  $1 million to restore the limestone balustrades to pristine condition, the statement suggested the signs were a justified effort to protect its investment from graffiti and vandalism.

That sentiment, along with the police cruiser, is something you might expect from an authoritarian state, not the city we proudly proclaim as the birthplace of liberty. So far, not a single board member has granted an interview to explain their thinking. Of the three emails I sent to three Friends' leaders, not one was answered.

Where's the accountability? Maybe it's a coincidence, but we've seen similarly high-handed behavior from other private parks groups. In the spring, Historic Philadelphia shocked many in the city when it cordoned off another of William Penn's original parks, Franklin Square, for seven weeks in the evenings to host a ticketed Chinese lantern exhibition. It happened again over the summer during the Democratic National Convention, when protesters were told they couldn't assemble on Dilworth Park, managed by the Center City District. Like the Friends of Rittenhouse Square, the boards that run these groups are largely controlled by powerful, monied, but unelected, bigwigs.

That isn't a criticism of the work these groups do. All three have devoted themselves to rebuilding parks that were neglected and underfunded by the city. The Friends have done a superb job of restoring Rittenhouse Square's original balustrades, fountain, and planting beds, laid out by Paul Philippe Cret in 1913. Though the city employs a full-time maintenance person to empty trash cans and flag graffiti, the square wouldn't be the beauty spot it is without the Friends' vigilance. All the landscaping is funded by their contributions.

When you put so much effort into a space, it's hard not to start thinking of it as your own. Pretty soon, you  start to feel you have the right to make the rules.

It's been suggested that the real motivation for the sitting ban was to discourage teens and others from smoking marijuana. Sure, that stuff goes on. Drugs were the motivation for the October shooting. Homelessness has also been a problem. But such behaviors can be handled with existing laws. Banning sitting targets everyone.

One of the wonderful things about Cret's design is the way it creates informal neighborhoods: the toddler zone around the goat, the lovers' lane around the perimeter, the bike messengers' break room at the corner of 18th Street, and, yes, the teen zone near the balustrades. A microcosm of the city, the park is the place where we learn to tolerate people who are different from us.

"What makes parks work is having as many types of users as possible," said Chris Bartlett, head of the William Way Community Center, who took to social media to condemn the sitting ban.

It's not only teens who hang out on the balustrade. I fondly recall the hours I spent there under the shade trees, watching my young daughter climb the bronze lion that she called "Aslan." The distance between the balustrade and the sculpture was just far enough that she could play without feeling a parent breathing down her neck.

Until those signs are removed, I would be considered a scofflaw. That's why I plan to stop by Tuesday's Sittenhouse, between noon and 1 p.m.

The mayor's communications director, Lauren Hitt, told me the administration intends to reevaluate its Rittenhouse Square enforcement policies, including the presence of the police cruiser. While they're at it, they should consider how to diversify the membership of the city's private parks groups. Only by including everyone can Rittenhouse Square remain a pristine and democratic space.