Already the SpaceX debris, err sorry, "starlink constellation" is causing problems:
https://twitter.com/esaoperations/status/1168534065118679042For the first time ever, ESA has performed a 'collision avoidance manoeuvre' to protect one of its satellites from colliding with a 'mega constellation'
This morning, ESA's Aeolus Earth observation satellite fired its thrusters, moving it off a collision course with a SpaceX satellite in their Starlink constellation
It is very rare to perform collision avoidance manoeuvres with active satellites. The vast majority of ESA avoidance manoeuvres are the result of dead satellites or fragments from previous collisions