Professor Cass Sunstein is controversially known for co-writing (with Richard Thaler) the book Nudge which promoted the idea that common commercial tactics such as influencing shoppers to buy items with better profit margins by placing them at eye level on supermarket shelves should be used by governments to encourage citizens to make choices favoured by those governments. However, an idea which seems even more important to him, since he's written three books about it, is the view that the internet is increasing social and political polarisation. In Republic.com (2001), Republic.com 2.0 (2007), and #Republic: divided democracy in the age of social media (2017) he examines the potential danger to democracy posed by the way normal human confirmation bias tends to be validated and exaggerated by the way the internet works.
As far back as the 1990s there was some recognition of the potential benefits and harms of the internet. For example, Robert Putnam's 1995 article Bowling Alone: America's Declining Social Capital (expanded and published in 2000 as Bowling Alone) and the 1996 paper by Van Alstyne and Brynjolfsson Electronic Communities: Global Village or Cyberbalkans? both expressed concern that the internet might replace normal real-world interactions with virtual interactions enabling geographically diverse but ideologically homogeneous individuals to form social groups potentially leading to increasingly extreme views and "calls-to-action".
There is now some evidence to support this view. The 2023 paper by Fergusson and Molina, 'Facebook Causes Protests, concludes "We find robust evidence that [Facebook] increases collective action. The effect appears when exploiting different levels of variation, including when we focus simply on within-country changes in Facebook access areas with different languages, as well as when we rely on media-based or individual reports of protest participation.
“Collecting data for various countries and over an extended period, we therefore confirm the external validity of previous research documenting this effect for specific contexts along a number of dimensions: geographically, by regime type, temporally, and by the socioeconomic characteristics of both countries and social media users. Informing the mechanisms that drive these effects, we find that the ‘’social’ nature of social media plays an important role beyond one-way information transmission.
“Also, we argue that these ‘coordination’ or social mechanisms reflect a ‘liberation' effect produced by having a direct outlet to voice opinions and share them with others. The intrinsic effect of having such access to a platform of social expression goes beyond tactical coordination, concerns about social image, or the effect of beliefs about others’ participation studied in the literature."
However, the study suggests that "...it would be overstating to conclude social media is unambiguously a 'liberation'' technology. As with any general-purpose technology, it has many other applications, so the broader (and changing) implications as different players adapt are still up for debate (J. A. Tucker, Theocharis, Roberts, & Barber´a, 2017). “Our findings suggest that protests against the opposition also increase, and that some additional mobilizations are violent – results that may have negative welfare consequences. More substantially, we show that the increase in Facebook access has produced no broader changes in the political equilibrium in the form of regime change, improvements in indices of democracy, and measures of governance."
It seems clear from this that the internet is a powerful tool for quickly encapsulating and spreading social undercurrents, but its loosely regulated nature can create problems when those ideas become consolidated into political ideologies while, at the same time, making those effects somewhat unpredictable. This is a recognisable feature of political blogs, particularly in the readers comments attached to the articles where other users are regularly exhorted to take their information only from those sources which are weighted in favour of the views preferred by the blog.
Given the virtual environment of the internet it's very easy to overestimate the number of regular users of any particular blog and, therefore, overestimate the popularity of those views especially if there are no dissenting voices. It's also very difficult to grasp the sheer volume of blogs available. Most estimates indicate that there are now over 600 million producing around two and a half billion posts annually. Of course, political opinion blogs only account for a small minority of this number, but that's still more than any individual can follow, and blogs work hard to increase their "stickiness" - that is, making sure that readers remain loyal - which means that most users rarely see more than a handful of blogs on a regular basis. On the other hand, people have many different reasons for using the blogs with many clearly just enjoying the companionship and the opportunity to blow off steam but there are significant numbers who present unsubstantiated claims to advance some agenda or other.
That this is a fundamental problem of human interaction is indicated by John Stuart Mill writing in the 19th century "It is hardly possible to overrate the value, in the present low state of human improvement of placing human beings in contact with persons dissimilar to themselves, and with modes of thought and action unlike those with which they are familiar. Such communication has always been, and is peculiarly in the present age, one of the primary sources of progress." We have Socrates to thank for setting philosophy on its path of questioning things people take for granted by providing opposing arguments and the Socratic method remains one of the most useful methods for analysing beliefs and opinions.
Back in the Sixties, Hunter S. Thompson wrote “We are living in dangerously weird times now. Smart people just shrug and admit they're dazed and confused. The only ones left with any confidence at all are the New Dumb. It is the beginning of the end of our world as we knew it. Doom is the operative ethic.” Whether he was right or wrong at the time, the claim remains simply an expression of his feelings (or perhaps the result of drug-induced paranoia) and, without any detail or empirical evidence to support it, has no significance or power to initiate a solution to the problem.