I saw this in Vancouver today, it looked like a web of strings tied to the branches of a cherry forcing it to assume a weeping form. Can someone let me know what it's about? Is it an acceptable practice?
That is exactly what it looks like, and is a fairly common practice to bring the branches to an easily harvestable level. I forget exactly what the practice is called, but it's normally used on Malus and Prunus trees (the pome fruits.) I do it to my young apple trees all the time.
Except these appear to be Japanese flowering cherries purchased grafted high on tall trunks specifically to elevate the naturally horizontal branches for clearance beneath. These may cost more than those not so treated. Weighing the branches down in an attempt to make them more horizontal is at cross purposes.