"In front of them stood seventy elders of Israel, and Jaazaniah son of Shaphan was standing among them. Each had a censer in his hand, and a fragrant cloud of incense was rising. He said to me, 'Son of man, have you seen what the elders of Israel are doing in the darkness, each at the shrine of his own idol? They say, "The Lord does not see us; the Lord has forsaken the land."' Again, he said, 'You will see them doing things that are even more detestable.'" NIV translation
We see that the leaders of Israel were in this little secret sanctuary bowing down to idols. These were the same elders that were sitting with Ezekiel in his house. They were saying in their hearts that they would replace God with all kinds of animal gods because He had abandoned them.