"You would need many billions (of people with laser-pointers), moreover with very steady hands on the part of all concerned.

The Moon is about 8 milliradians wide, and laser-pointer spots are ~0.3 milliradians in width. They output at most 5 milliwatts and most are 2 or less, and you would need to overwhelm Earthshine from
the Moon, which is roughly 0.1 W/sq.meter.

Your common spot on the Moon would be about 1/30 of a lunar diameter, or ~130 km in width, or ~10,000 sq.km or 10 billion sq.meter in area. Thus, you would need a billion watts of total laser-pointer illumination to overwhelm Earthshine, or the output of 500
billion laser-pointers.

Of course, if you were to look at the Moon with
spectral filter glasses which just matched the ~2 nm spectral-width of the laser-pointers, you would cut this illumination requirement by ~500-fold, so
that 'only' one-sixth of the human race -- one-third of those who could point at the Moon at any given moment -- would have to point to the same spot
on the non-Sunlighted portion of the Moon in order to see a doubling of the apparent illumination there -- which is not greatly in excess of human
visual-intensity threshold at low light levels."