Judicial Activism

[crash]

I thought judicial activism meant striking down laws the legislature has passed. I was under the impression that Thomas et. al. were anti-judicial activism. How to explain this:

"Indeed, according to an analysis by Paul Gewirtz, a professor at Yale Law School, and his student Chad Golder, of Supreme Court decisions between 1994 and 2005 addressing the constitutionality of sixty-four congressional provisions, Breyer voted to strike down laws twenty-eight per cent of the time—less often than any other Justice. Clarence Thomas voted to overrule Congress sixty-six per cent of the time, more than any other Justice."

link

How to explain? Maybe it only counts as judicial activism if you strike down a law in a certain area? e.g. economic

(note: I'm not trying to be snotty)