A report from England suggests they are.
Facebook is wrecking criminal trials, according to detectives.
Victims and witnesses using the social networking site to identify a suspect are jeopardising justice, police have warned.
The National Detectives Forum, a specialist unit which advises the Police Federation, has revealed that a number of trials have collapsed after victims and witnesses played detective, browsing Facebook and Twitter to find a suspect.
In one case, a victim who was attacked outside a house party looked on Facebook to find the man who attacked him after searching the friends of the person holding the party.
The suspect was arrested for the assault.
But evidence from the identity parade which the victim picked him out from was ruled inadmissible when it emerged that both the victim and witnesses had viewed the suspect's Facebook photograph numerous times.
The case collapsed and no further action was taken against the suspect.
Now detectives are calling for legislation to prevent victims carrying out their own inquiries on the web to track down offenders.
. . .
The warning comes just weeks after Britain's top judge ordered that jurors be given formal warnings about using the internet to find information about defendants whose cases they are considering.
The Lord Chief Justice said that if this information was allowed in any way to influence a verdict, it could lead to the quashing of a conviction.
Lord Judge issued new guidance at the Court of Appeal that jurors needed to understand that 'although the internet is part of their daily lives, the case must not be researched there'.
Appeals are starting to reach the courts where defendants claim their trials were jeopardised by jurors resorting to information from personal computers, mobile phones and social networking sites.
There's more at the link.
I hadn't thought of the reality of living in an online world as affecting criminal investigations and trials, but it makes sense. If potential witnesses have seen (or been shown) pictures of the person against whom they're to testify, before they do so, it calls the accuracy of their testimony into question; and if jurors are judging a defendant on material they've looked up themselves, rather than what's been presented as evidence, it makes a mockery of the trial process. This could get tricky . . .