No different than Uganda taxing "social media" for everyone.  The net effect was that the popular quickly discovered decentralized and federated social media - a very positive effect.  The law is only effective on centralized "social media" that requires registration.  The Uganda govt was paywalling IPs of large centralized outfits like Twitter, Facebook, LinkedIn, etc

Someone will have to look at the Florida law in detail to see if 3rd party registration (such as for Activity Pub sites run by someone else) is prohibited.  Yet another incentive to run your own or go fully decentralized.