Forum users and blog commenters can still remain anonymous to most of the other users. But some of the most serious tools of anonymity look to be easily pierced by determined governments.
After the Edward Snowden revelations about how the US government was spying on US citizens some of the tech gurus were advocating use of Tor to thwart the spies and skip around the internet anonymously.
However, Tor isn't such a good place to conceal one's internet usage after all. The FBI used some dubious tactics to dig out some purveyors of kiddie porn who were hiding in the Tor tunnel. See Visit the Wrong Website, and the FBI Could End Up in Your Computer. It's a good story.
The Netherlands police had a web crawler written which would collect every Tor address it could find in that portion of the web not revealed by the typical search engine. They found one in 2011 with an administrator account without a password and went to work on it to find the owners location. It was in Nebraska, and they turned it over to the FBI.
The FBI watched it for a year while developing malware which would find out who was visiting the site. In 2012 they arrested the operator and and installed drive-by downloads on his three servers. The downloads would infect each computer that visited the sites and reveal their IP addresses, hardware MAC addresses, a Windows host names. They obtained that information on at least 25 visitors to the site, some of whom are currently on trial.
Apparently, just visiting a kiddie porn site is illegal. That's a good reason to keep anyone else from using your computer, and pity the poor person who stumbled on one of those sites accidentally.
As for the FBI malware, apparently it wasn't a one time deal. And as with any new technological tool, there's plenty of opportunity for abuse. combine malware that provides an opportunity to spy on anyone regardless of their attempts to hide and an environment in which political opponents are singled by a government, and there's a problem that should worry us all.