Kaitnieks is a Latvian programmer and former RuneScape Classic player. Known as an early pioneer of RuneScape cheating, he first played RuneScape in 2001 and was involved in the cheating community until roughly 2006, when his forums were closed. He wrote the RuneScape bot AutoRune, as well as the programmable macro SCAR. AutoRune was sold in 2004, before this the source code was leaked. The program was discontinued and stopped working due to Jagex's updates.
Kaitnieks means "saboteur" or "pest" in Latvian and was a nickname given by Kaitnieks' employer.
He has not been involved with RuneScape since roughly 2006, and stopped playing years before that.
His website is still available, however, the cheats are no longer usable, it hasn't been updated in a long time, and many links are dead, including the forums.
Kaitnieks "never played RS much", but had a character named "sulaspaka" with 99 mining and 86 smithing. It was approximately level 40 so it could survive the spiders by the Wilderness rune rocks but high level players couldn't attack it.
He also had a team of consisting of 1 smelter, 4 iron miners and 6 coal miners. The smelter only smelted, the other members mined coal and iron and autotraded to the smelter. The character had level 76 smithing from smelting only.
Kaitnieks abused a now-fixed glitch allowing him to attack bankers in RuneScape Classic by equipping a bow and using AutoRune to create "attack" commands.
On 7 November 2003, a friend of Kaitnieks named Sixfeetunder learned how to create any non-stackable item using AutoRune while attempting to trade the untradable Scythe holiday item. This was done by sending a command to add zero of the item to the trade, which caused one item to be added to the receiving player's inventory, effectively creating new items.
The bug was leaked to five AutoRune users - Kaitnieks, Dylock, g0ne, Axel, and David. They then participated in spawning rare items and creating dragon square shields (worth millions at the time) to high alch them. Many players were banned, however, the spawned items were not removed from the game, permanently effecting the prices. The price of party hats crashed afterwards and the pink (now purple) hat changed from being the most expensive to the least expensive, allowing the blue hat to take its place as the most expensive.
Kaitnieks took screenshots of him and his friend Dylock spawning Christmas crackers and pulling them on random players in Varrock Square, then a popular trading hub.
This is popularly known as the "Great Party Hat Dupe" due to the popularity of Xx Jut Xx's website's documentation of the event.