2013-Apr-18: A new lower limit to the redshift of the PKS 1424+240 has been published (arXiv:1304.4859). PKS1424+240 was discovered in the VHE band by VERITAS and this new limit makes it the most distant VHE-detected blazar ever, with potential implications for the measurement of the gamma-ray opacity at VHE energies. See the UCSC press release here.