Mining the Sky for Blazars

We use a large sample of blazars to provide new constraints on the spectral energy distributions and energetics of AGN jets. We have discovered a new population of X-ray loud flat-spectrum quasars, missed by previous radio surveys. The new class are the strong-lined counterparts to high-energy peaked BL Lacs, with UV/X-ray synchrotron peaks. Once these sources are included, we do not find agreement with the blazar sequence scenario. A more complete account of this work has recently appeared (Padovani et al. 2003).