As the Web becomes an ever more important part of business, it's also becoming an increasingly rough neighborhood. For instance, distributed denial of service (DDOS) attacks -- the practice of flooding websites with so much incoming traffic that they can't operate properly -- increased by nearly 700% between 2004 and 2005
, according to security firm Symantec. Attacked e-commerce sites can be knocked offline for days, losing millions in sales. These attacks are done not by teenage pranksters, but by e-commerce competitors (some from countries where cybercrime laws are lax), or customers who feel wronged. Symantec also notes the practice of using "bots" -- hacked "zombie" PCs that can be remote-controlled and directed to flood a site with traffic. Some hackers rent out the bots they control, acting as digital hit-men.
Meanwhile, "click fraud" in web advertising is on the rise
, with scam artists learning how to manipulate ads from Google and others. One estimate claims that click fraud activity accounts for 20% of all Internet traffic, and costs advertisers up to $1 billion every year. Click fraud has become such a problem that it caused Standard & Poor to downgrade Google's stock to a "sell" rating in January. As with DDOS attacks, click fraud is conducted by sophisticated criminals who often use bots and zombies.