"But to the wicked God says" (50:16). Who are the wicked in this psalm?

The psalm describes them by what they say and do, and names no one. They speak God's words: "What right do you have to declare my statutes, that you have taken my covenant on your lips" (50:16). But they "hate instruction" and "throw my words behind you" (50:17). God lists what they do: "When you saw a thief, you consented with him, and have participated with adulterers" (50:18), "You give your mouth to evil. Your tongue frames deceit" (50:19), and "You sit and speak against your brother. You slander your own mother’s son" (50:20). He calls them "you who forget God" (50:22). The psalm doesn't say whether they are among the "people" God speaks to in 50:7, or apart from them; it says they have his covenant on their lips (50:16). And it doesn't end on them. Its last words are for anyone: "Whoever offers the sacrifice of thanksgiving glorifies me" (50:23).