With just a couple photos of your key, a growing number of websites are offering to make a copy of your key. Unfortunately, there is no way for these businesses to verify that the person who sends in the images is authorized to have a duplicate key made. They say they can track who ordered the keys, but to prosecute someone who has had keys made to someone else's property, the police would have to know where to look. See the story at http://www.clickorlando.com/news/cyber-locksmiths-surge-in-popularity-prompt-security-concerns/27884712.
What can you do? Altic Lock Service advises you to use great care with the handling of your keys. Keep them in your pocket or purse. When you take your car in for service, leave only the car key, not the whole key ring that includes your home or office key. The locks we carry use standard replacement cylinders, so you can use less common keyways. Almost all locks sold at hardware stores use one of only a couple of different keyways. The shape of the head of the key will often identify the keyway. We prefer to use neuter-bow keys because the keyway cannot be determined simply by looking at the head of the key. You don't need to spend money on high-security or restricted keyways. Just using less common key blanks will thwart most unauthorized key copiers. Many local hardwares have difficulty identifying the key blanks even when they have them in hand.