Epistemic action, we suggest, demands spread of epistemic credit. If, as we confront some task, a part of the world functions as a process which, were it done in the head, we would have no hesitation in recognizing as part of the cognitive process, then that part of the world is (so we claim) part of the cognitive process. Cognitive processes ain't (all) in the head!
They go on to say:
In these cases, the human organism is linked with an external entity in a two-way interaction, creating a coupled system that can be seen as a cognitive system in its own right. All the components in the system play an active causal role, and they jointly govern behavior in the same sort of way that cognition usually does. If we remove the external component the system's behavioral competence will drop, just as it would if we removed part of its brain. Our thesis is that this sort of coupled process counts equally well as a cognitive process, whether or not it is wholly in the head.For the most part, the focus of Clark and Chalmers is on immediate interactions with the environment, as when we physically rotate objects rather than mentally doing so, or when we count on our fingers (using them, in their view, as a form of external working memory). However, I think one of the more interesting aspects of the internet is the way in which it serves as a sort of external long-term memory store. I think we can view the use of the internet for the storage and retrieval of information as a form of active externalism, or an instance of the extended mind, as well.
The primary criterion Clark and Chalmers discuss for treating the use of the external environment during cognitive tasks as part of an extended cognitive system requires that the external entities serve the same purpose as internal processes (i.e., the external and internal processes are causally systematic). I think the use of the internet as a long-term memory store meets this. Take search engines, for example. Often we may read something on the internet, and encode the gist of it. However, the details are either not encoded, or weakly encoded. We don't need to encode them. Using our knowledge of the gist, we can simply search the internet using keywords (retrieval cues), and quickly retrieve these details. We can then use this information to structure our knowledge of the domain on-line. We may even use the internet to store and retrieve information about ourselves. Blogs, for instance, serve as extended memory stores for our previous ideas, and articles we've read. Searching their archives, or using search engines to find previous posts, can therefore be an economic way to retrieve information about ourselves.
In these situations, the external information serves the same purposes that internal information in memory would. Much as we would when retrieving internal memories, we use retrieval cues to search for information, and that information then serves to structure our representations. Furthermore, the retrieved external information may serve to cue the retrieval of further autobiographical memories about inferences we had previously made based on that information, much as the retrieval of stored representations would. Thus, the internet, as a long-term memory store, appears to be part of an extended cognitive system used for retrieving and reasoning about information in extended long-term memory.