From an article in Fast Capitalism 2:2, "Compliance Fiction: Adorno and Horkheimer's 'Culture Industry' Thesis in a Multimedia Age" by Sam Caslin.
Basically, Caslin uses Adorno to call bullshit on "co-creation" -- marketers' beloved exploitation of consumers to do their job for them: "the actions of the Firefly/Serenity fans suggests an increasing rationalization of consumer culture whereby fans are no longer required to simply consume passively but to become actively involved in the mechanisms of production and market creation." In the same vein as Holt's awesome article about consumer refuseniks.
Co-creation is not an escape from passivity so much as it is a voluntary plunge into deeper exploitation at the level of fandom, of libidinal investment, or whatever you want to call it. The fans would deny that they are being exploited at all, of course, which moves them to a different level than those who cynically "see through" advertising and marketing but use the products and champion the brands anyway.
A good point about the limits of the term "culture industry": "the culture industry thesis critiques a specific type of gentrified, mass-produced artefact aimed at legitimating capitalism" -- that is, what defines culture industry product is that it engenders a specific sort of consumer, or audience that is predisposed to function within capitalism and would feel threatened when it is threatened -- it inculcates a dependence on capitalist structures for obtaining pleasure and self-knowledge, the commodities of knowledge and recognition and social know-how that have been disembedded from earlier modes of distribution. Entertainment is reified, etc., experience is commodity to collect rather than an immersion in the present unmediated (if such an ideal is possible).
"although consumers may have some power within consumer society this only negates the potential for them to have power over consumer society. Modes of production cannot be controlled or challenged from within." This also seems like it might apply to the internet and digital media -- if social media is the problem itself, it can't really be used to undo itself. Social media is a new way for capitalism to homegenize experience and re-present it as "content." What we win through such media strengthens the system that is depriving us of a larger freedom.