As more groups get into the denial-of-service attack business they’re starting to get in each other’s way, .

That translates into a smaller average attack size, said Martin McKeay, senior security advocate at Cambridge, Mass.-based

There are only so many devices around that have the kind of vulnerabilities that make them potential targets for a botnet. “And other people can come in and take over the device, and take those resources to feed their own botnet,” he said. “I’m seeing that over and over.”

McKeay said that Akamai is seeing evidence of the contention in the threat intelligence it gathers, as well as in the size of the attacks. The median attack size has been decreasing over the last year and a half, he said. At the start of 2015, the median DDoS attack size was 4 gigabits per second, and it went down to just over 500 megabits per second during the first quarter of this year.

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