A read of the COBE and WMAP teams' papers on the methods they used to produce 'contamination-free' maps (or, to remove all 'foregrounds') is exhilarating. However, unless I missed it, these methods largely address emission in the wavelengths of interest (i.e. those which the various instruments detect) - zodiacal light, free-free emission, warm dust, distant 'point sources', etc. The only exception is the SZE (Sunyaev-Zel'dovich Effect - inverse comptonisation of the CMBR by hot electrons in the ICM of rich clusters), an effect which has now been unambiguously detected for several clusters, and which holds much promise as an independent probe of many cosmological parameters and processes. OTOH, Copi et al. (and several others) have identified anomalies in the quadrupole and octopole CMBR, viz, a lack of power (cf inflation-based cosmological model predictions), and curious, 'non-fluke' coincidences (esp with the ecliptic). So, two general questions: 1) irrespective of known processes, plausibility, etc, to what extent could absorption rob the l = 2 and 3 multipoles of power? 2) irrespective of observed examples, and sky distribution, what physical processes (other than the SZE) could give rise to absorption in the relevant wavebands?