The Dragon Rune Lance has been disabled for players of Fortnite. The announcement was made Monday, the morning of June 13, by @FortniteStatus, the official Twitter account for all Fortnite service updates.
The Dragon Rune Lance is a harvesting tool used by players to gather building materials. It is part of Chapter 3: Season 3's Dragon Rider Set, and is available through the game's Battle Pass for 950 V-Bucks, according to Fandom's Fortnite Wiki page.
Dragon Rune Lance in Fortnite Disabled
The video, which as of this article has over 500 thousand views, shows plainly that sprinting in the game while holding the pickaxe, allows the player to move silently making them harder to detect by other players nearby.
In other words, this pickaxe could give the player wielding it the ability to sneak up on other players. It should also be noted that the player wielding the tool is also more vulnerable to sneak attacks, as they are also not able to see the footstep icons of would-be attackers while wielding it.
Although this is no doubt a glitch rather than a feature of the Dragon Rune Lance, it would be interesting to see if purchases of the Lance were affected positively in the 2-day span between the release of GKI's video on June 11, and the announcement of it being disabled on June 13.
Either way Epic has done the right thing, and the Dragon Rune Lance should be back soon in its fair, intended form.