"Since October 6th, Occupy Houston, in cooperation with the City of Houston, has been a model for what a safe, effective protest can be," occupier Dustin Phipps intoned at a press conference on Wednesday.

Put the emphasis on has been.

For that good rapport was damaged late Tuesday. On the same day that Houston experienced a tornado touching down in Kingwood and the closer-than-expected reelection of Mayor Annise Parker, the Houston Police Department admonished and arrested Occupy Houston protestors for using a tarp for shelter.

Occupiers say that police forces descended upon their camp at Tranquility Park after their nightly 7 p.m. General Assembly, where Sheila Jackson Lee served as the guest speaker Tuesday night. Officers found fault with the group's tarps, saying that one structure protecting equipment and medical supplies violated a city ordinance that bans tents on city property, except in inclement weather.

On Monday, several Houston Police Department officers had stopped by the camp to explain why one of Occupy Houston's structures at Tranquility Park broke that ordinance: Stakes were pinned to the corners of a tarp, thereby transforming the plastic piece of material into a "tent." Occupier Jamin Stocker said that the officers explained how to bypass the rule by removing the stakes and wrapping the edges of the tarp around chair legs.

Officers on shift Tuesday night didn't recognize any distinction though. Whether or not the stakes are there, a tarp becomes a tent if it provides shelter in their view — and protestors were sitting under it.

The protestors refused to retreat or dismantle the structure. Officers threatened to make arrests and confiscate materials. Several hours and many failed attempts later, police reinforcements arrived (occupiers counted "approximately 27 HPD officers in approximately 19 squad cars" at one time).

By the end of the standoff, seven occupiers were arrested, dragged to the paddy wagon and forced to spend the night in the city jail. Arraignment took place this morning for three, but charges and fines remain unclear for the rest.

The Houston Police Department ticketed, detained and quickly released three others present (including a member of the National Lawyers Guild and his wife) for jaywalking, though protestors claim that the crosswalk was blocked by squad cars at the time.

Officers disassembled the makeshift structure, seizing the supplies beneath. Other tarps covering supplies and materials were left untouched. In YouTube videos posted by Occupy Houston, protestors can be heard chanting, "Shame! Shame!" as the HPD moves in.

Occupiers see the arrests and the confiscation as a violation of their First Amendment right to peaceably assemble and a detriment to their safety and health. Phipps hopes that the conflict will result in an open dialogue between the city and the protestors about how they can continue to protest safely throughout the winter months.