When was this? When WebGL was a new thing, there was no protection whatsoever and an uninitialized textures and buffers could contain stale data from other proc

When was this? When WebGL was a new thing, there was no protection whatsoever and an uninitialized textures and buffers could contain stale data from other processes. But this has been fixed like a decade ago. In any case, what you saw is not what is described by this article. This article extracts pixel data very slowly by measuring GPU timings.