Grid formation of trails is often used to indicate that the trails is sprayed deliberately. Chemtrail debunker do not leave this alone, like metioned bellow:
The link explained that grid happen because of the wind. The jetplane passing the same route but the wind blow the previous trail to previous position. Creating many trail that form a grid.
The explanation look logical, however, it leave out these phenomena:
1. Some people observed that the grid is made in random order. The trails is not sprayed in sequence but in random order. The next trails is always fill the sky that never been sprayed before with precision. With only this it is enough to dispell wind blowing trails theory, but there is more.
2. The trails is created very fast, in minutes. The wind should never has time to move the trails fast enough.
3. Grid still observed on no wind condition. It is often seen that the trails do not move position. If grid is formed by the wind then the trails should be moving. But the grid still seen even if the trails stay at their location. The jetplane that spraying the trails definitely use different route.
4. The grid also seen to has even distance between one trail to the others. This precision can only happen if the spraying is done deliberately.
5. The wind theory can not explain why there are criss crossing trails.
All the above reason show that wind can not be used to explain the grid formed by the trails. Indicating that the spraying may indeed deliberate.