  We discuss HI and optical evidence for ongoing ICM-ISM interactions in 6
HI-deficient Virgo cluster spiral galaxies. One of the clearest cases is the
highly inclined Virgo galaxy NGC 4522, which has a normal stellar disk but a
truncated gas disk, and lots of extraplanar gas right next to the gas
truncation radius in the disk. Unusually strong HI, H-alpha and radio continuum
emission are all detected from the extraplanar gas. The radio continuum
polarized flux and spectral index peak on the side opposite the extraplanar
gas, suggesting ongoing pressure by the ICM. Four other HI-deficient edge-on
Virgo spirals show evidence of extraplanar ISM gas or exhibit asymmetries in
their disk HI distributions, but contain much less extraplanar HI than NGC
4522. Comparison with recent simulations suggests this difference may be
evolutionary, with large surface densities of extraplanar gas observed only in
early phases of an ICM-ISM interaction. In NGC 4569, the H-alpha image shows 2
effects of ICM pressure on the galaxy ISM. An anomalous arm of HII regions,
possibly extraplanar, emerges from the edge of a truncated H-alpha disk. This
resembles the arms seen in simulations which are formed by the combined effects
of wind pressure plus rotation. An extended nebulosity near the minor axis,
also in the NW, is interpreted as a starburst outflow bubble disturbed by ICM
wind pressure.
