Anonymity clearly changes how individuals communicate, but the research I know of tends to focus more on how people like to behave badly and mischievously when there is no known reputation or name associated with the consequences of a action.
Anyone who has spent any time on the internet knows the ability to obscure identity, however thin or unsophisticated, elicits changes in behavior. I highly doubt the producers of these tools construct them with the goal of inviting mayhem in mind. Regardless, the more anonymous a data transfer is, the less social pressure there is to communicate within certain permitted boundaries.
Outside of a authority point of view, there's also the potential for creativity and free association related to anonymity. If one feels you won't be judged because of saying something, you might open up.
" In the past decade there hasn’t been a year without a politician calling for real names on the internet. Some even want to force people to use real photos as profile pictures. All in the name of stopping online hate, though enforcing real names has long been shown to actually make the problem worse.
This article presents another solution, one that has actually proven that it keeps communication friendly, even in the most anonymous environment of the fully decentralized Freenet project.
And that solution does works without enabling censorship."
Considering the content accessible through such services, their best use by far is as honeypots to catch dangerous criminals.