Why? Religious people commit less crime, get and stay married more, use less illegal drugs, donate and volunteer more... It would make more sense to fear people becoming less religious.
Source?
Source?
For crime see my comment below (or above, remains to be seen).
Afaik about american statistics, the poorer, lower class groups, are more religious -- e.g. "white trash", latinos and black ghetto cultures. So there is no overrepresentation of those, e.g. blacks, in jail...?