The immediate circumstances was the failure/refusal of the local newspaper, the Bloomington Pantagraph, to cover the extremely intense civil-rights struggles then going on in Cairo, Illinois. (Those struggles were led by a black minister. I forget the name of his organization, but its logo was a bible on which rested a revolver.) Already by 1969 pedestrian traffic in downtown Bloomington has become a dribble, as retailors shifted to malls to the east of downtown, so leafletting or demonstrating there had become a pretty empty exercise.
First two women in SDS visited the editor, asking him to increase coverage and indicating our intentions to publicize as widely as possible the failure of the paper to cover events in Cairo. (We characterized that failure, and I think we were correct to do so, as deliberately racist.) He of course merely sneered at them. We then prepared (in fact had already prepared) a leaflet on Cairo and the Pantagraph, and put up a token picket line outside the paper's entrance in downtown Bloomington.
Then seven members of SDS began passing out leaflets inside the large local mall (owned by Sears at that time, Sears being its "anchor store" or whatever they call it). They were not to enter any of the retail stores themselves but merely to distribute leaflets in the public concourses.
All seven were arrested. We got the Illinois State ACLU to represent us, and they did provide one of their better attorneys from Chicago to handle the case.
By the time the case came to trial, movement activity was unravelling, and only one of the original 7 was still involved. The local court of course held by the mall. It was several years later (I don't remember exactly when) when the case was finally rejected by the U.S. Supreme Court.
However: when activity such as that that developed in either the '30s or the '60s again appears, it should be possible to break into the malls, court decisions or no decisions. Large enough numbers of people could easily develop tactics that would simply make it more convenient for the Mall owners to allow demonstrations than to fight them off.