How much weight should you give to a stranger's opinion?
If you ask YouTube, the answer is: not much.
The video sharing website has made changes to the way users can comment on clips. Google, which owns the website, now requires them to sign up to its social network Google+ before they can post their thoughts.
Its justification? It says the move will help it customise the order comments are displayed in and give users more tools to moderate posts about their videos.
"Would you rather see comments from people you care about... or just whoever in the world was last to post?" it asked on its blog.
But the move has caused many users to voice displeasure about the changes.
A petition on change.org calling on Google to scrap the move has received nearly 200,000 signatures.
One of the concerns expressed by people supporting it is that by requiring users to have a Google+ profile the firm was taking away their anonymity.
"It's ethically wrong to force these changes onto an unwilling user base as it alienates them while devaluing the quality of the site and tarnishing your credibility," posted Aaron Vollhofer.
It is perhaps not surprising that Google's move has sparked such a reaction.
Over the past few years the internet has provided a medium for people to express their thoughts and opinions on just about anything. Many of them did so under the cloud of anonymity.
But that has also given rise to a problem - trolls and other rude and uncivil online commentators who sometimes end up dominating the discussions.
"A user posting comments under an anonymous username is much more likely to post in ways that are offensive, unfair and reactionary," Robin Hamman, managing director of Dachis Group Europe, a social business consultancy, told the BBC.
"Giving people the shield of anonymity is basically inviting trouble."
Mr Hamman added that firms were trying to tackle the issue by getting people to create proper profiles.
"You get much more considered, truthful and honest opinions expressed in forums where it is easier to link their comments back to the real names and profiles, which may have a bearing on their professional and personal lives," he explained.
YouTube is not the only website to alter its policies on user comments in recent months.
In August news website Huffington Post announced it would no longer allow comments from anonymous accounts.
It said it was doing so because "trolls have grown more vicious, more aggressive, and more ingenious. As a result, comment sections can degenerate into some of the darkest places on the internet".
The firm said nearly three-quarters of the comments on its website "never see the light of day, either because they are flat-out spam or because they contain unpublishable levels of vitriol".
Then in September, Popular Science, the science and technology news website, shut off all comments on its site. It also blamed trolls.
"We are as committed to fostering lively, intellectual debate as we are to spreading the word of science far and wide," the website said.
"The problem is when trolls and spambots overwhelm the former, diminishing our ability to do the latter."
It cited research from the University of Wisconsin, which suggested that intemperate comments could polarise readers and skew their interpretations of a news story.
Some analysts say that the problem with vicious comments stems from the fact that firms were not fully ready to tackle the massive and rapid growth in user interaction.
They say that while companies have been keen to engage in two-way conversations with the public as a way to boost their business, they have not been fully prepared for the costs involved.
"When firms open the forum and comments on their websites they think that user-generated content is a cheap way of bringing more life to their page," said Mr Hamman.
"Unfortunately that's not the case. It needs investment, both in technology and manpower to monitor this.
"By the time many firms realise this - the damage has already started to be inflicted," he added.
However, moderating comments can introduce its own issues.
The BBC, for example, screens posts added below stories on its news website. The move limits the number of stories that can be commented upon, leading some of the discussions to feature complaints from readers criticising the choice of articles.
YouTube and Huffington Post's solution also only goes part of the way to banning trolls.
It's not that difficult for someone to create a fake profile using a fictitious email address and start posting comments.
However, the sites hope that by putting up extra hurdles they may be able to at least discourage some of the troublemakers - or perhaps divert them elsewhere.