The threat of epiphenomenalism is indeed a major issue intensively discussed in the last decades. But while there is a broad consensus against it, there is no agreement as to what exactly blocks it. Burge in Foundations of Mind (Ch. 20) even says that the dominance of materialism in the contemporary philosophy of mind is a reaction (in his view unwarranted) to the epiphenomenalism anxiety. The simplest resolution would be physicalism, mental states are reducible to physical states, then of course there is no problem with them affecting the physical. So far physicalism was unsuccessful in reducing even classical chemistry to quantum mechanics (in fairness, the problem is incredibly complex for technical reasons), and with reducing mental to physical the added difficulty is understanding what that even means for qualia, consciousness, volition, etc. Physicalism still has many supporters, but its popularity somewhat waned.
With that non-reductive materialism and dualism gained in popularity, but there the problem manifests itself in the form of causal exclusion argument articulated by Kim. First, it is widely believed that microphysical states (of the brain in particular) are causally complete, i.e. what happens to electrons, etc., depends only on their quantum state. This does not necessarily mean determinism, the point is that nothing other than their physical state at time t can influence their physical state at later times. Even that may not determine it fully, but causally completeness excludes any additional co-determiners. Since physical effects can not be caused twice over the state of the brain can not also be affected by “mental states”, whatever they are, unless they identically reduce to something physical. Thus, there is no top down causation from mental to physical, and mental has no physical influence. Just like images on TV screen have no causal influence on the physical state of the TV, even if we can often predict what will happen next in a movie from them alone.
Some materialists, and causal dualists, do reject causal completeness of the microphysical, e.g. the Stanford Disunity Mafia (this is a nickname for a group of analytic philosophers which includes Dupré, Hacking, Suppes and Nancy Cartwright). Dupré in Metaphysical Disorder and Scientific Disunity argues that it as a hasty generalization from toy examples in tightly controlled laboratory conditions, which are far removed from either brain’s environment or complexity. This blocks the causal exclusion argument, but a plausible account of top down causation has not yet been offered any more than a physical reduction. Penrose's speculations about quantum gravity causing collapse in the brain microtubules are quite fantastic, and Kauffman's explanation that "mind does not act causally on brain at all, rather it acausally decohers to classicity (for all practical purposes), hence has consequences for brain and body as matter" is rather obscure. In principle, top down causation might even be consistent with some future version of physicalism, but that would seem to require developments in physics far beyond our current state of the art. See also Top-down Causation without Top-down Causes by Bechtel and Carver for a deflationary view of top down causation consistent with traditional physicalism.
The middle path between reduction and top down causation is supervenience, the idea that mental changes "track" physical changes, but do not collapse into them. The idea originated in Davidson's Mental Events (1970), and Yablo (1993) and Bennett (2003) gave (what looked like) promising constructions of the tracking. In them the mental is so intimately related to certain physical aspects that bringing about one necessarily brings about the other. So one could say that when knowledge, etc., affects our actions we are strictly speaking referring to its physical companion, but the difference is technical as the two are inextricably linked. Unfortunately, these constructions of tracking were recently shown not to work, see Exclusion, still not Tracted by Keaton and Polger (2014). But the general approach remains attractive to non-reductive materialists.
The intuition against epiphenomenalism is strong and widely shared. The problem is not that people doubt that information should make a physical impact somehow, but that no one can explain how.