How is stealing from a wifi connection any different than stealing cable or satellite TV? There isn't a physical product that you're stealing but people still go to jail and are successfully prosecuted for it. I mean, isn't it the cable or satellite company's fault for not scrambling their signal off or making it impossible for jacking into their network? How about stealing phone service? Is that wrong simply because price is clearly equated with minutes of service so you know how much exactly you're stealing?
You may not think you're making an impact, but you could be crippling their internet. If you overwhelm their upload bandwidth, you can make even web surfing impossible for them.
And justifying it by saying "they shouldn't be stupid and leave their network unprotected" is just an excuse for being a prick or a thief. Let's apply this mentality to other things.
I steal your wallet. You should have been smart enough to hide it better instead of leaving it in your back pocket for me to take. You weren't robbed, you're just sharing your extra cash with everybody else. You'll still receive more money next week to spend on things so it isn't like you won't have more money in the future. I'll return your wallet too since that is an item you paid for. Your credit cards I'll keep, purchase a bunch of stuff on them, and then send them back to you afterwards. So I didn't steal your credit cards either.
I steal your car because you were in a hurry and left your car keys in it while it was parked in your driveway. You should have been smart enough to take the keys and lock your doors so it isn't considered stealing anymore. Oh, maybe you did lock your doors and took your car keys, but Virus and his buddies Trojan, Worm, Malware, and others broke into your car and primed it so you can start it without a key. It is your fault that you don't repeatedly check on your car to make sure it is running perfectly so it is still alright I took your car without your permission then.
I steal your crop as a farmer because you appear to have plenty and you didn't put a fence up to keep me out. It's not like the farmer relies on it as a source of income. Besides, you're only one person so it isn't making a noticeable impact. But then it is two people and three people and four people and dozens and then soon the farmer doesn't have a crop left. but you only stole a few ears of corn as did everybody else.
I steal your electricity from your house and use it to power my house, but it is alright even though I had to trespass on your property because you didn't secure your power supply enough and it isn't like you can own electricity. I mean, can you stick it in your pocket? Nope. So no stealing their either.
Or, you don't lock your doors to your house and I simply move in. I use your water; your electricity, your furniture, your appliances, your beds, your rooms. I'm using your entire house without paying any rent but what exactly am I stealing? I'm not stealing something physical from you; yet I am still enjoying something that you would be charging me for free of charge.
Just because you can't stick something in your pocket or hold it in your hands doesn't mean you're not stealing it. That is why we have patents and copyrights to protect intellectual property. That is why colleges will flunk you and kick you out in a heart beat if they discover you plagiarizing your papers. Just because radio waves don't respect physical boundaries and the majority of people aren't computer literate doesn't make it right to take advantage of them. Is it right to take advantage of the ignorant or mentally handicapped because they don't know better? What about even the smart simply because you're capable of scamming them? Acquiring something for free that you normally would have to pay for is thievery and blaming the victim is simply the justifications of a thief.
