JIRA backlog needs a lock button to prevent accidental re-arranging of tasks

As a user of JIRA's software,
I would like a lock button (defaults to on) that prevents issues from being re-organised
So that I don't accidentally move issues around when scrolling on a touchscreen device.

Basically, JIRA is nigh on impossible to interact with using a "pocketable" mobile device. (In my case, ZTE T83 with the Firefox web browser.) Not only does the UI need lots of screen real-estate (a problem even on many laptops with 1366×768 pixel screens), but in the backlog, the (small!) elements respond to dragging events almost instantly.

This is exacerbated by having minimal space to stick ones finger that isn't a task entry. The end result being when tapping on tasks or attempting to scroll, the task is often moved to a wildly different position. Add some lag, and you've got a recipe for making a right dog's breakfast of the carefully curated ordering of tasks.

The tasks should be fixed in their position, unless the user explicitly tells JIRA that they wish to alter positions, indicated by a padlock icon or similar, at which point the old behaviour should be restored allowing re-arrangement of tasks. The same UI element should also make it possible to re-enable the lock.

(Thanks to Nic Brough for pointing this JIRA instance out to me.)