Miranda and the Silent Treatment:
Check out United States v. Thogsophaporn, a fascinating Miranda case I found via Appellate Law & Practice.

  Facts: Defendant is taken into custody and read his rights. The defendant is asked to waive his rights but he declines. An investigator then sits down in the small interview room with the defendant in silence for five minutes, three to five feet away from him, until the defendant asks for some water. The investigator brings it to him, and then the defendant asks what is going on. The investigator responds that the defendant knows what is going on, and the defendant asks if the police want to talk about him ratting on a cocaine dealier. The investigator then brings up the fact that his colleagues want to talk to him, and the defendant then agrees to talk and waives his rights and confesses.

  Legal question: Is the confession admissible under Miranda?

  Held: Yes, the statement is admissible, because the defendant was the one who reinitiated questioning when he asked what was going on. The court explains:
  [T]he agent’s mere silent presence in the room is insufficient to rise to the level of unlawful coercion or pressure. Indeed, because the agent was required to avoid discussions concerning defendant’s legal situation, it is hard to find any fault at all in his silence. While silence may feel awkward or uncomfortable under some circumstances, there is no requirement that the police engage in small talk. Nor was the agent required to exit the room and leave the defendant unsupervised. See United States v. Andrade, 135 F.3d 104, 106-07 (1st Cir. 1998) (upholding admission of statements obtained following period in which the defendant did not want to answer questions and slept while officer remained in room). . . .
  In summary, there was nothing improper about [the investigator's] presence in the room or his silence. At no time did [the investigator] attempt to resume questioning or persuade defendant to speak. Defendant was the one who initiated the conversation about his situation
  My reaction: I don't know of any other cases on this particular technique, but this case has my b.s. detectors going off big time. Imagine you're in a police interrogation room with a police officer sitting three feet away from you, completely silent. Maybe he's staring right at you. Maybe he's staring at a wall. After a few minutes, the silence is likely to become unbearable; you're going to at least ask something general like "what is going on?" But presumably you won't know that this kind of general inquiry was held in Oregon v. Bradshaw to be enough to reinitiate questioning (however persuasively), so you're not going to realize that you've just gone back to Miranda square one.

  Meanwhile, presumably the officer does realize this; presumably he is making you sit there with him in a very uncomfortable situation knowing full well that you're likely to eventually ask what is going on. Cf. Missouri v. Seibert. If the test is whether the police "scrupulously honored" the defendant's choice to remain silent based on the totality of the circumstances, I find it rather hard to believe that this type of technique fits the bill. Perhaps there are previous cases allowing this sort of technique that I just don't know about, but it certainly seems fishy to me.