“How about hezek reya”
AAQ. I’ll certainly defer to your familiarity with the gemorah in Bava Basra but my vague recollection is that the issue was not entirely clear as to whether ‘gazing’ on to your neighbor’s property and activities is to be considered is a real hezek and was assur or whether there had to be some real physical damage to trigger compensation or whether the concept was more applicable to private activities undertaken by your neighbor which if witnessed by others could cause an ’embarrassment’ (a component in determining compensation for injuries). I thought that halacha put the obligation for building a wall or some physical barrier was derived from a socialized obligation to avoid real physical damages in common areas for the common good. A clear, line-of-sight view from one neighbor’s property to another doesn’t obligate either to block their view of the other but certainly each has the option of doing so to the extent they wish to protect their privacy.
When the Lerner family built the Nationals Stadium, they left a portion of the center field wall open knowing that new condos in the neighborhood would have a view of the playing field. I believe the gemorah contemplated tha if one neighbor repeatedly performs activities without active protest from the other neighbor ( a form of chezkat tashmishin?) Would chezkat tashmishin apply to gazing rights? I have no clue but perhaps there was an implicit waiver of any rights to seek damages since the Rav living in the condo had no obligation to close his window blinds and block his view anytime the Nats were playing a home game. I could see a potential haalachic issue (along with an obvious tort under civil law) if he publicly advertised tickets to sit in his living or on his balcony to watch the Nats game.