I recently looked at a homebuilder who used spliced together boards for framing. Is this normal or even safe?

1. Boards were spliced or shark-toothed together 4 times on an 8 foot board.

2. I know they did this to save cost, but how long will it last?

3. Know of any websites to find the differences in lumber grades?

4. Also searching for a website to show pictures or discuss this splicing technique.