There's at least one group of Pittsburgh residents that hasn't been up in arms about the property reassessment: the Occupy Pittsburgh demonstrators who've been camped out on Mellon Green. And yet they too are fighting over the ground beneath their feet, opposing BNY Mellon's attempt to remove them from the Downtown parklet.

Yesterday, in fact, attorneys for Occupy Pittsburgh filed their response to BNY Mellon's lawsuit to evict them.

BNY Mellon is seeking a court injunction to oust the protesters. The bank argues that it could be held liable for any harm that the protesters cause or incur -- from attempts to keep warm during the winter, for example. (BNY Mellon cites online requests made for propane tanks and other heating equipment as the basis for its concern.) The bank also argues that while the space is typically open to the public, BNY Mellon maintains the right to close it off ... and that it typically does so during the winter.

Occupy Pittsburgh's response -- which refers to the site not as Mellon Green but the "People's Park" -- was submitted by Mike Healey and five other attorneys, among them University of Pittsburgh professor Jules Lobel, a scholar of Constitutional law. As you might expect, the response asserts that demonstrators have a First Amendment right to their protest. What's more, while it acknowledges that BNY Mellon owns the site, it rejects the idea that this "has any impact on [the Occupiers'] legal rights" to demonstrate there.

Much of the dispute centers on arguments over zoning provisions that apply to open spaces, and how much leeway a property owner has to close off public access to them. The Occupiers argue, as they have from the outset, that zoning rules governing "urban open space" bar Mellon from shuttering the site. (BNY Mellon's original complaint contends that most of the site is governed by a different set of rules for open space. More about this later, perhaps: The argument is too tedious for a Friday afternoon.)

In any case -- and here's where we get to the heart of the matter -- the response says BNY Mellon gave the Occupiers "a license to occupy and use and People's Park" ... and having done so, it can't remove them now.

The Occupy attorneys note that when the Occupation began, on Oct. 15, Occupiers were told by Pittsburgh Police Lt. Ed Trapp that they could stay as long as they respected the site. Mellon later issued a set of guidelines to Occupiers "for the duration of the occupation of Mellon Green"; rules included a ban on weapons and drugs, the removal of tripping hazards, disposal of trash and waste, and "no open flames."

Before Mellon posted a notice of eviction, the legal response contends, BNY Mellon said nothing about closing the park for the winter. Nor did its eviction notice -- posted on the site Nov. 9 -- allege that any of the guidelines had been broken. Occupy attorneys surmise that the real reason the bank seeks to evict demonstrators is that the Occupiers "began publicly criticizing [BNY Mellon]" based on their belief that the bank has "engaged in and continues to engage in corrupt and immoral financial practices."

Meanwhile, the Occupiers argue, once BNY Mellon had extended its seemingly open-ended permission to remain on the site, demonstrators "solicited and expended substantial sums of money, hours of labor, and in-kind donations preparing to 'winterize' their camp." The response cites more than $7,000 worth of donations in cash and equipment; since the Occupiers incurred those costs "in reliance on [BNY Mellon's] statements," it argues, the bank "may no longer legally revoke at will the license they gave [Occupy Pittsburgh] to use and occupy the People's Park."

We may find out next week whether that's true: Common Pleas Court Judge Christine Ward, who is hearing the case, scheduled a hearing on the matter for Tuesday, Jan. 10. Occupiers are calling a protest that same day.