“Keep in mind that social networking sites like MySpace did not exist until recently,” said Nick Akerman, a New York lawyer who has written and lectured extensively on the act. “This case will be simply another important step in the expanded use of this statute to protect the public from computer crime.”

Image Tina Meier, mother of internet teen suicide victim, leaves a press conference after speaking to the media after the guilty verdict was handed down. Credit... Jonathan Alcorn for The New York Times

Other computer fraud experts said they found the verdict chilling.

“As a result of the prosecutor’s highly aggressive, if not unlawful, legal theory,” said Matthew L. Levine, a former federal prosecutor who is a defense lawyer in New York, “it is now a crime to ‘obtain information’ from a Web site in violation of its terms of service. This cannot be what Congress meant when it enacted the law, but now you have it.”

Ms. Drew, who showed little emotion during the trial, sat stone-faced as the clerk read the jury’s verdict and left the courtroom quickly, her face red and twisted with rage.

Her lawyer, H. Dean Steward, said outside the courthouse that he believed the trial was grandstanding by Mr. O’Brien in an effort to keep his job, with the coming change in the White House.

“I don’t have any satisfaction at all,” Mr. Steward said of the verdict.

Judge Wu scheduled a hearing on the request for a new trial for late December.

Since the story surrounding the suicide became public last year, Mr. O’Brien has discussed with his staff how his feelings as a parent motivated him to bring the charges against Ms. Drew. He alluded to those feelings on Wednesday at a news conference.

“This was obviously a case that means a lot to me,” he said.

The case has been a collection of anomalies. Judge Wu appeared ambivalent regarding some key issues at the trial, like whether any testimony about Megan’s suicide would be allowed (he did allow it) and how to rule on a defense motion to throw out the charges (he had not ruled as of Wednesday).