U.S. District Judge Dee Benson has rescheduled DeChristopher's sentencing for July 26. He faces up to 10 years in prison.
DeChristopher's group, Peaceful Uprising, organized Thursday's rally at Exchange Place and said backers in 40 other cities also demonstrated outside their federal courthouses. Activists intend to conduct civil-disobedience training Friday at Liberty Park.
The Salt Lake City protest attracted the Rev. Billy Talen of the Church of Stop Shopping, a New York-based performance artist who made headlines with such stunts as exorcising cash-register demons at chain stores he opposed in city neighborhoods. He has formed an "Earthalujah Choir," which plans to tour Europe to advocate against climate change.
Talen met DeChristopher last year when both were protesting mountaintop-removal coal mining. Talen said he was arrested a sit-in at a Washington, D.C., bank that finances the mining in West Virginia.
He said Thursday he wanted to learn from Peaceful Uprising coordinators and take home their civil-disobedience tactics.
Many Americans are trying to sound the alarm against their country's carbon-based economy, Talen said, but the alarm is "disabled by government and corporate marketing and police."
"It is a time to become radical Americans again," said Talen, whose church draws on many faith traditions in a "post-religious"movement.
"Loving the Earth is a faith," he said.
Talen will perform Friday with one of his choir members at the activists' barbecue at Liberty Park around 6 p.m.
Several Salt Lake City police officers watched DeChristopher's speech to about 40 supporters. Rallies during his trial attracted much larger crowds and a strong police presence but encountered no reports of trouble.
DeChristopher's message Thursday invoked the memory of the freedom riders of the early 1960s. Those activists rode integrated buses through Mississippi, he said, until enough of them were jailed under that state's Jim Crow laws that the Kennedy administration was forced to act.
The same will happen, DeChristopher predicted, and quicker than most believe if enough people sacrifice their freedom fighting for the end of the fossil-fuels industry and the "corporate governance of this country."
"If you do stick your neck out," he said, "people will come from out of nowhere and have your back."
That has been his experience since monkey-wrenching the auction, DeChristopher said, and the movement will grow as more people practice civil disobedience on behalf of the planet.
Activists said whatever happens to their friend will only embolden them.
"We won't be deterred," Salt Lake City resident Flora Lee Bernard promised. "We won't be shut down."
P Peaceful Uprising's eco-activists plan to conduct a "boot camp" Friday starting at 10 a.m. capped by a barbecue at 6 p.m. in the northeast corner of Salt Lake City's Liberty Park. On Saturday, they plan to single out area businesses as climate-change offenders or models of progress.