Paul overstays his welcome in Ephesus, and ends up causing a riot. The lectionary reading from this past Sunday, about Paul baptizing in Jesus' name those who had only received John's baptism, can still be the source of riots between Christians. But later on in chapter 19, Paul's teaching against idols leads to a full blown street protest, which gets left out of the lectionary.
Demetrius, a silver worker in Ephesus, who makes his living by making small statues for pilgrims to take home with them (religious kitsch in the first century!), notices that his chance to make money is going down as more an more people are following Jesus and worshiping at the temple of Artemis. He works the rest of his colleagues up into a frenzy, but succeeds only in getting sent back home by the town clerk.
Idols, though they are not alive, have a pull on our hearts and our wallets (the way to our hearts is through our money - "Where your treasure is, your heart will be also" Jesus said). We are so intent on keeping our idols safe that we will riot in the streets! But it is in the quiet way of Jesus, who shows us how to worship the Living God, that we find our truth and our peace.