- There are malicious bots (and botnets) of the following types:
- Spambots that harvest email addresses from contact or guestbook pages
- Downloader programs that suck bandwidth by downloading entire web sites
- Website scrapers that grab the content of websites and re-use it without permission on automatically generated doorway pages
- Viruses and worms
- DDoS attacks
- Botnets, zombie computers, etc.
- Bots are also used to buy up good seats for concerts, particularly by ticket brokers who resell the tickets.[citation needed] Bots are employed against entertainment event-ticketing sites. The bots are used by ticket brokers to unfairly obtain the best seats for themselves while depriving the general public from also having a chance to obtain the good seats. The bot runs through the purchase process and obtains better seats by pulling as many seats back as it can.
- Bots are often used in Massively Multiplayer Online Roleplaying Games to farm for resources that would otherwise take significant time or effort to obtain; this is a concern for most online in-game economies.[citation needed]
- Bots are also used to increase views for YouTube videos.
- Bots are used to increase traffic counts on analytics reporting to extract money from advertisers. A study by comScore found that 54 percent of display ads shown in thousands of campaigns between May 2012 and February 2013 never appeared in front of a human being.[5]
- in 2012, reporter Percy von Lipinski reported that he discovered millions of bot or botted or pinged views at CNN iReport. CNN iReport quietly removed millions of views from the account of so-called superstar iReporter Chris Morrow.[6] It is not known if the ad revenue received by CNN from the fake views was ever returned to the advertisers.
- Bots may be used on internet forums to automatically post inflammatory or nonsensical posts to disrupt the forum and anger users.
The most widely used anti-bot technique is the use of
CAPTCHA, which is a form of
Turing test used to distinguish between a human user and a less-sophisticated AI-powered bot, by the use of graphically encoded human-readable text. Examples of providers include
Recaptcha, and commercial companies such as Minteye,
Solve Media, and
NuCaptcha. Captchas, however, are not foolproof in preventing bots as they can often be
circumvented by computer character recognition, security holes, and even by outsourcing captcha solving to cheap laborers.
