Class Action were from Cambridge, Massachusetts and they released one great ska EP in 1984. They later recorded four more songs which were produced by Don Dixon (Marshall Crenshaw, R.E.M., Counting Crows, Hootie and the Blowfish, etc) but only one "Thieves' Market" was released. You might remember it from the first Mash it Up compilation from 1986. In 1987 they changed their sound to more of a college-rock style but they maintained a bit of their old ska influence and recorded a single and the album "Things You Left Behind" - which included the song Thieves' Market.
Class Action EP (1984) A1 - It All Comes Back to You A2 - If This is Love B1 - Getting Nowhere B2 - When the Wind Touches Down
"If this is Love"
Things You Left Behind (1987)
1 True Love on the Radio 2 Thieves' Market 3 One by One 4 Die for One Day 5 Two Minutes to Midnight 6 You Can Run 7 Could I be the One? 8 Moral Majority 9 Eyes 10 Changes Inside of Me