When you're buying and selling investments online, it pays to be extra careful to make sure your personal and financial information doesn't get stolen by cyberthieves. At the very minimum, you should protect yourself by

  • Locking down your computer. You'll want to install antivirus software — software that protects your files from malicious code — on your computer at the very least. Better yet, install firewall software or enable the firewall software built into your operating system. A firewall puts a fence around your computer, letting you control what data comes in and what goes out.

  • Be extra careful of wireless connections. If you're online using a public wireless Internet connection, you need to be especially cautious.

  • Checking up on your brokerage. Before you give money to anyone, be sure to run the broker or brokerage firm through the Financial Industry Regulatory Authority's online BrokerCheck tool. This simple search will only take a few moments and will tell you if the broker or brokerage firm is permitted to sell you securities.

  • Knowing what's reasonable. You should have a grasp of what kind of returns you can expect from investments. Knowing what legitimate investments return will help you smell a sham a mile away. If someone promises "guaranteed" or "risk free" returns that exceed the return of stocks, you know you're most likely being lied to.

  • Getting familiar with regulators' resources. The Securities and Exchange Commission offers free and tremendously helpful tools and tips to investors. Take the time to explore the site and you'll be a much better investor. A great place to start is by checking out brokers and financial advisers. It's easy. Just click on the Check Out a Broker or Adviser link under the Education tab.

    Another great resource is the North American Securities Administrators Association, which puts you in touch with your state regulator in two clicks. Just click the Contact Your Regulator link on the left side and then click your state on the map.