Without pics or measurements it's impossible to give an accurate answer.

Shrinkage cracks are standard. As it cures, concrete shrinks about 1/16" per ten feet.

The mandatory government warranty programme Construction Performance Guidelines I work under say the following about poured concrete foundation wall cracks:

"1.11
CONDITION
CAST-IN-PLACE CONCRETE FOUNDATION WALL IS CRACKED
Acceptable Performance/Condition
Cracks resulting from normal shrinkage are acceptable; cracks in excess of 6 mm in width are
not acceptable.
Warranty
One-Year Work and Materials

Cracks resulting from normal shrinkage of materials caused by drying after construction
are excluded from the statutory warranty.
Action
Walls with cracks exceeding the acceptable condition shall be repaired.
Remarks
Concrete walls naturally crack during curing due to shrinkage. Where lateral or vertical movement
is evident, further investigation may be required.
The colour and texture of a repaired area may not match the surrounding concrete"

I linked to the prior Guidelines. However, latest edition, 2012, has no change for this issue.

**
If your foundation has a bubble membrane waterproofing there should be no water penetration problem for hairline cracks. If the cracks grow a bit more, the standard fix is a polyurethane injection.

Thanks for the reply. The cracks are hairline, but there is water penetration since all along the crack it was wet. The crack starts at the corner of a basement window and zig zags vertically down to the basement floor. It's not a straight zig zag, but it rather zig zags down and left (from the inside) and down an right (from the outside)

Here is a link to flickr to see photos of the wall:

Here is a link that might be useful: Cracked Wall Photos

It looks like a typical minor shrinkage or settlement crack that can be fixed by injection as in the picture I (double) posted.