Do bare protons exist, even transiently, in aqueous solution?
According to Myths about the proton. The nature of H+ in condensed media Accounts of Chemical Research, vol. 46, pp 2567–2575:


  But to put this into
  perspective, an electron-free proton has an estimated acidity $10^{56}$(!) times greater than 100%
  H2SO4, the threshold of superacidity.$^2$ Adding a bare proton to a molecule is a real event in the
  gas phase but only a solvated hydrogen ion can be transferred in condensed phases.