Quantum ergodicity studies the behavior of the mass distribution of Laplace eigenfunctions as their eigenvalues increase. In the arithmetic setting, Eisenstein series provide a natural family of such eigenfunctions, and the problem naturally leads to familiar number-theoretic objects such as L-functions. I will discuss a generalization of quantum ergodicity for Eisenstein series to arithmetic hyperbolic 3-manifolds attached to imaginary quadratic fields of arbitrary class number. A key point is a reconciliation of the classical and adelic viewpoints on automorphic forms, which becomes necessary in the higher class number case.