Careful when removing and untangling it from plants. Even the smallest little piece left behind will regenerate and continue to grow.
Very annoying thing to deal with. I got plants from plantedaquariumcentral a few months ago and had a ton of this stuff all over my Najanshen, took almost 3 hours to clean it up but luckily have only spotted one strand of it since then. Quarantine helped to lower the infestation for sure.