One collectible activity is the Data Fragments, of which there are 45 to collect or 'shoot' to be clear. They can be found in weird and wonderful places - I'll pop up a quick short video to show what they are as I can't find a pic online.
EDIT Important note - You have to shoot them with the corresponding weapons:
- White - Kinetic Weapons
- Coloured - Energy Weapons
- Red Haze - Valkyrie
There are 2 main rewards from this hunt. One at 35 fragments and one at the full 45 fragments.
At both stages there is a cache you have to find to open to get the rewards.
At 35, you can obtain Destiny 2's first exotic sword, Worldline Zero.
At 45, you obtain an Exotic Sparrow.
Quite a cool treasure hunt that takes a while (not if you're ultimate hardcore, like Datto) and seem cool rewards to obtain. I really like how you have to shoot them rather hold square on them. Makes a nice change.