https://www.newscientist.com/article/2153032-tinfoil-hat-for-your-router-stops-bad-guys-snooping-your-wi-fi/

Now there may be a quick and relatively easy solution to these Wi-Fi woes.

Researchers at Dartmouth College in Hanover, New Hampshire, have developed customised reflectors that can precisely control the shape of the Wi-Fi signal from a router.