Most Internet traffic has nothing to do with people downloading porn, playing online poker or shopping at Amazon (AMZN).

In fact, people aren’t even responsible for the majority of online traffic, according to a new report. Industry research firm Incapsula finds that 61.5% of Internet traffic is the result of automated software, commonly called bots, the BBC notes.

Incapsula tracked 1.45 billion visits to 20,000 selected websites by bots over a span of three months. The study found that bot-generated traffic is growing, up 21% from last year.

While it may sound alarming, bots actually perform routine functions like compiling analytics and indexing website content. Such legitimate bot-use comprises the largest part of the rise since last year.

However, some bots have been designed by hackers to illicitly collect personal data or promote online fraud. Such bots have become less common recently.

The study found that bots that automatically post links to spam content sank 75% in the recent study, while hacking bots fell 10%. Unfortunately, bots that improperly impersonate legitimate entities climbed 8%.