What was the thing with url's not being sanitized that grimoire revealed?

like with this note:

nostr:nevent1qqszj2s2093gpvta9mvaprt3j9mlpskynjprex2tu0sytqfz0x24n8qpr9mhxue69uhhwmm59e3xzumnwp5hxar0dshx7un89upzq0c34wewydw694xa5htdavh3yvtnga48gk3u545ftgws7ce2gt6qqvzqqqqqqyqmynm2