Late last month, for an early round of attacks against WikiLeaks that drove the group off its usual servers and onto ones operated by Amazon.

The increasing popularity of DDoS attacks, and the enormous publicity they received when groups attacked sites belonging to companies that had pulled the plug on services to WikiLeaks -- including Bank of America, MasterCard and PayPal -- worries Zuckerman.

"I have concerns that the sheer visibility of DDoS attacks and the fact that they demonstrate some pretty effective techniques [to shut down a site] will lead to a rash of DDoS attacks against human rights sites," said Zuckerman.

And often, there's little a victimized site can do to fend off DDoS attacks.

Typically, human rights or dissident media groups can't afford to contract with hosting providers that are large enough to stymie even small- or mid-sized DDoS attacks, said Zuckerman, or they're hesitant to use a major hosting provider because they suspect it will censor their site or toss them overboard at the first sign of controversy.