As laws struggle to keep up with technology, it's hard to know what's legal

Hewlett-Packard has shone a light on the gray world of snooping.

But big corporations aren't the only ones who hire private eyes. In fact, private detectives say about half of their clients are individuals with domestic situations -- the classic case being the scorned spouse trying to out the cheating spouse.

Private detectives also get hired to find deadbeat parents behind on child support and to investigate whether an ex-spouse is living with someone and not entitled to receive alimony.

The other half of their work is corporate -- i.e. working for insurers trying to show people are faking disabilities or injuries, or for companies that suspect a worker of stealing.