The next time you need to book an airline seat, you're likely going to face some annoying competition: bots. 

Online bots have become a well-known issue in recent years, thanks largely to their role in politics. Accounts that spread information--or misinformation--while appearing to be human have invaded social-media sites, namely Twitter. 

But bots can do much more than disseminate propaganda. They can try stolen username-password combinations across hundreds of websites at once, for example, or scoop up event tickets for the sake of re-selling them at a higher price.

A report released Wednesday focuses on the role that bots play in the airline industry. The company that conducted the study, Distil Networks, specializes in detecting bots and denying them access to a website or mobile app. It collects data on a user's online behavior--such as how it moves its cursor across a page or whether it clicks a button perfectly in the center--then feeds the info through a series of algorithms to make a determination on whether a user is a human or a bot. San Francisco-based Distil counts among its clients StubHub, Yelp, and Crunchbase.

This past summer, Distil tracked user activity data on 100 airlines' websites worldwide. Over the course of 30 days, it analyzed 7.4 billion requests to determine whether they came from humans, bad bots, or "good bots," such as those that crawl websites for the sake of improving search results. 

The primary finding: 43.9 percent of all activity was from bad bots. 

Bad bots can be used for a variety of things on an airline's website. Competitors and other third-party sites can use them to gather price and flight information, which doesn't necessarily cause direct damage to the customer but does add to the amount of infrastructure the airline needs to keep its website running smoothly.

Then there's the issue of seat spinning: A third-party booking site can hold a seat in its cart, then resell it at a higher cost on its own website before completing the purchase on the airline's site. This makes it far easier for those sellers to earn a markup, since there's no investment required on their end--they're not buying the seat until they know they've resold it for higher. According to Distil, this problem is most prevalent in the Asia Pacific region, where seats can often be held for 24 hours, but it does happen in the U.S.

Most maliciously, bots can be used to hack into a rewards account to use points or airline miles. Unlike the previous two cases, this type of activity is illegal, since it's the equivalent of stealing actual money. And it's the only situation that you, the customer, can be proactive about by using strong, unique passwords.

According to Distil, 21.8 percent of Web traffic across all industries comes from bots. Among the industries the company has studied, only gambling had a higher percentage than the airline industry's 43.9 percent. 

Of the 100 airlines the company studied, 51 of them saw more than 50 percent of their total traffic come from bad bots. 

Frequent flyers, beware.