Newsflash to the French! There are two trials in the United States - one inside the courtroom and one outside. The First Amendment allows the media to put defendants and prosecutors through their paces before they even step inside the courtroom. Reporters don't wait for courts to tell them what justice is; they investigate for themselves. Sometimes they put defendants in an uncomfortable spotlight; sometimes they exonerate them.
I don't condone perp walks or unfair pretrial publicity. It is unprofessional and unethical. But, in my experience, it doesn't really matter what the media does. Dominique Strauss-Kahn will get a fair trial. I have personally witnessed many high-profile cases, from O.J. Simpson's murder trial to Michael Jackson's molestation case. Kobe Bryant was once branded as a rapist, yet he ended up walking away from that case. Simpson and Jackson were both acquitted.