They attended at Saint Isaac Jogues School in Hinsdale where Lenczycki was an associate pastor at the time.
The former priest was held past his prison release date because he was considered too dangerous.
Some who protested outside the DuPage County Courthouse on Thursday were outraged about the judge's decision.
"He's going to reoffend. I know that. He's a very sick individual and he needs to be put away," said abuse survivor Peter Hillmer.
Lenczycki was believed to be the first Roman Catholic priest in the country to be legally declared a sexually violent person.
