Enabling comments leads to slant

[W]hen you and I can contribute to an online newspaper, there's a surprising effect on the real-world version. The print versions of the papers become more mild in terms of the opinions expressed (particularly those of a political bent), while conversely, the online versions of the papers become more slanted, either to the left or to the right.

David R. Bell, Location Is (Still) Everything: The Surprising Influence of the Real World on How We Search, Shop, and Sell in the Virtual One (Seattle: Amazon Publishing, 2014), p. 136 (citing Pinar Yilirim, Esther Gal-Or & Tansev Geylani, "User-Generated Content and Bias in News Media," Management Science, vol. 59, no. 12 (Dec. 2013), pp. 2655-66)