xD its not a tracker its what happens when u hit f3 and B at the same time
it is built in to minecraft

 

On a Mac u press fn f3 b and on a pc u press f3 b. not a hack built into minecraft and u cant see the box when someone goes behind a wall and the blue is their vision area.

 

it comes on everyclient bought, and can work for everyone, the blue lines are for 1.8 only though
sorry to make u sad about ur assumptions but I don't even know how to down load optifine

 

@bobman3355 thx for having a education of mincraft

 

You welcome :D its super helpfully it also boxes items i always use it

 

whoops im sorry about the evidence thing, I didn't know that the website did that, so sorry about that

 

"F3+B: Toggle visibility of hitboxes of entities, and in 1.8 shows which direction entities are looking in using a blue line"

Please do your research on vanilla clients. Not that you've ever used one

 

@lolelf123 I fixed the picture pls edit in this link for the appropriate border so sorry about the picture thing, [Mod Edit]

 

Thank you for filing this complaint. However, as has been stated above, this can be done by using "f3 + b" on a 1.8 client. As this is a vanilla feature, it is perfectly legal. Also, when filing complaints like this in the future I will suggest you link back to the original source of the screenshot as it will be needed.

As well I will be editing out the screenshots due to language contained within.

Locked, this is a vanilla feature.