Akamai Technologies provides caching and redundancy for web sites dealing with heavy request volume. "Akamaized" sites, in theory, should be able to stand up to any volume of traffic and withstand most denial-of-service floods. In other words, Akamai provides exactly the kind of service Al-Jazeera has needed for its English-language site, which has been under heavy stress since the start of the war in Iraq and has seen repeated episodes of extended unavailability.
Akamai, however, has cancelled its contract with Al-Jazeera, and is refusing to provide an explanation. Al-Jazeera, for its part, claims that Akamai caved to the "political pressure" against helping out a site that has been the target of intense anger in the U.S.
Regardless of whose explanation you believe, the episode underscores Akamai's power as an Internet gatekeeper. Akamai's approval may mean the difference between "existing" and "not existing" as far as the Net-going public is concerned.
I personally think it becomes appropriate to worry whether such power is being exercised arbitrarily; at the very least, Akamai owes the world a fuller statement of its reasons for ending its relationship with Al-Jazeera.