  Two new Mg II absorbers are presented (z=1.340 in S5 0454+844 and z=1.117 in
PKS 2029+121), bringing the total number of Mg II systems in the 1 Jy
radio-selected BL Lac sample to 10. Five of the ten absorption systems are at W
> 1A; this is a factor of four to five greater than the number expected based
upon quasar sightlines, and is 2.5 to 3 sigma greater than the expectation
value. Interpretations of this possible excess include either that some of the
Mg II absorbers might be intrinsic to the BL Lac or that there is a correlation
between the presence of absorbing gas in the foreground and the nearly
featureless spectra of these BL Lac Objects compared to quasars. Such a
correlation can be created by gravitational microlensing as suggested by
Ostriker & Vietri. The similarity between the optical spectra of BL Lacs with
Mg II absorption and the spectrum of the Gamma-ray burst source GRB 970508
suggests that models of Gamma-ray bursts as microlensed AGN should be
investigated.
