Unless someone else is paying for the electricity to run these computers, the heat isn’t “free” by any stretch of the imagination. Also, during the summer months, you’ll have to pay extra to cool the room because these ‘heaters’ are always running, or there isn’t much point in them.
I'm thinking only people in certain climes would be interested.
What someone needs to do it turn all radio waves into heat. I have about 50 wifi connections pretty close to my house.
Something you can plug anything into, IE phone lines, cable that somehow turns it all into heat.
There “free” energy!
Might be able to heat a very small space. lol