Sometimes popular Web sites on your servers just suck up your bandwidth, slowing down your servers or Internet connections.
Wouldn't it be good to throttle back their output so as not to overload you server and your Internet connection?
Mod_throttle was created for this purpose. It can be configured to regulate Web sites on a per-virtual host or user basis.
You specify how much of the bandwidth each site can use. When a site exceeds its allotment, connections to it are delayed or temporarily blocked.