Some general advice for those who may not be aware:
Most importantly, do not rely on this forum for action if you are concerned at the harassment you have experienced. Whether that be due to its nature or severity or a fear of escalation. Unless you are simply asking Zwift to add a feature to their wishlist you MUST make a formal complaint of harassment to Zwift support. Otherwise it will not be acted upon with the speed and sincerity it may require, if at all.
If you receive a follow request from someone that you are avoiding just ignore them and leave it sit there. While it is active they cannot send another request. If they retract the request and then send again make a note of the action you have taken, ie, deliberately ignoring and leaving it active. The sender’s repeated retraction and resending will be stronger evidence that they know exactly what they are doing. This may serve you well if you need to press the issue with Zwift HQ or, heaven forbid. law enforcement.
Under Settings > Privacy in the companion app you can turn the Private Messaging toggle to ‘on’. When turned on you will only receive private message from people you follow. That way, if someone you are avoiding wants to try to communicate in game they will have to do it in open chat. If they are bold enough to do that then you can screen shot it and it is likely that others will see it too.
If you run Zwift on Mac or PC you can access the log files for your 10 most recent rides and see a full transcript of all chat (open and private chat) that can be used as evidence if you need to approach Zwift or law enforcement. I don’t use Mac, but on PC the folder location is C:\Users"your name"\Documents\Zwift\Logs. If you show the date and time stamp in your file system it’s easy to find the log file you want.
If you want to Zwift with no other users to do a workout or whatever and avoid the a holes and creepers you can login and start your ride, then disconnect from the internet. For many people that will mean disconnecting their Zwift device from WiFi. Leave it disconnected for the duration of your ride and then reconnect before you finish your ride. Make sure you are connected before you exit the ride and the usual upload process should occur. Then close Zwift as normal or do another ride. Follow the process again if you want the next ride to be by yourself.
You can, of course, set your profile to private, but that doesn’t stop the unsolicited follow requests. Just makes it a tiny bit harder for the mouth breathing pond life to keep track of your movements.
As has been mentioned in this thread already, going private is undermined somewhat if you are friends with people who have an open profile. In this case changing your profile name doesn’t help as anyone paying attention will notice a change of identity among a consistent following or follower list.
There are a number of ways to discover your Zwift ID such as the above mentioned ride logs and in Zwiftpower to name two. So messing with your own profile by constantly changing name is a waste of time against a determined harasser. Just makes it harder for your legit friends to tag you for meetups, etc.