Lastly, if you find out about one online compromise, be prepared for others. My friend's account was compromised via another website, where the attackers gained access to his home address and other information, which was used to answer questions on the stock site when they were updating his account contact information.
Luckily, the worst thing that happened to my friend was having to delete over 7,500 spam messages, one by one. Take note: If my friend had seen all the spam messages and did one massive delete, as he was originally tempted to do, he could have missed the real stock trade notifications -- and failed to shut down the operation before any real damage was inflicted.
People still ask me if it's safe to do online banking or shopping. I always say yes because most fraud happens when the bank or vendor's credit card database is compromised -- which will usually impact your transactions whether on or offline.
But the best reason to do online business is that you can check your balances and transactions anytime you like. I don't have to wait for a credit bureau to let me know days later that unauthorized activities has occurred. In fact, I can act immediately at the first signs of trouble and thwart the attackers before the damage is done.
This story, "Do's and don'ts for online traders," was originally published at InfoWorld.com. Keep up on the latest developments in network security and read more of Roger Grimes' Security Adviser blog at InfoWorld.com. For the latest business technology news, follow InfoWorld.com on Twitter.