There doesn't have to be "direct evidence" for there to be a guilty verdict. Circumstantial evidence does not necessarily mean "bad evidence". I find it intriguing that people one or more thousands of miles away from Italy, who presumably got their information about this case from "the media", claim (a) to know that Knox was innocent (b) that the jury (who are in Italy and who have heard all the evidence and seen Knox in court) were influenced "by the media" to find her guilty.
A jury member has said that said no one on the jury had been influenced by the lurid newspaper headlines during the trial. They are Italians, they know their own media.
The New York Times quotes Senator Maria Cantwell, (Dem, Washington) as saying “I have serious questions about the Italian justice system and whether anti-Americanism tainted this trial.” She added, “The prosecution did not present enough evidence for an impartial jury to conclude beyond a reasonable doubt that Ms. Knox was guilty.”
So she raises the spectre of "anti-Americanism" by saying she has "questions" about it. That is a bit like saying "I have serious questions about whether Tremula eats babies" for no other reason than to blacken Tremula's name. Also I don't know how she (or anybody else who was not present at every day of the trial) can possibly know that the prosecution did not present enough evidence to convince an impartial jury. Jury members have stated that they were impartial, and they were convinced enough to bring in the verdict that they did.