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How safe is it to leave your wifi public? I have a few computers (Mac, PC) would I be putting those computers on the network in danger? Or would it be a case of just burning bandwidth, and possible use for criminal activities?

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closed as not constructive by Breakthrough, Wuffers, slhck, Linker3000, alex Jul 4 '11 at 8:13

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.

Keeping your WiFi network public is a stupid idea, regardless of where you live. If you lock your front door, why not lock your network? Or, better yet, just let me know the next major intersection to you - I'll show you why it's not good to leave your WiFi unencrypted. :) – Breakthrough Jul 2 '11 at 19:39
So many stories of neighbors surfing child porn on someone else's open network, then the police busting down the door of the wrong person, now you have some explaining to do while you are in Jail. – Moab Jul 2 '11 at 19:50
The reason to leave it public is a service for our customers (pub), however I wanted to know if it would be ok to use the home wifi. – PhilCK Jul 3 '11 at 10:28
Can you clarify the situation more? Do you want to use a single wifi access point for both pub and home use? – nealmcb Jul 3 '11 at 16:34

While it sounds like a neighbourly thing to do, it does put yourself at risk.

Use Facebook? It is trivial to hijack someone's account if you're on the same LAN. Same with many other online services that you may use.

Also, depending on the laws in your country, you could be held liable for actions taken "from" your network. So, someone using your network could launch a cyber-attack from your network, download child pornography or perhaps infringe copyrights and you'd be held liable.

Lock it up.

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Just a side note: Yes, it's trivial to hijack somebody's Facebook account if you're on the same LAN, but only if you're not using SSL. -> Account Settings -> Account Security -> Browse Facebook on a secure connection (https) whenever possible. That is the key to not having your Facebook account hijacked, regardless of whether or not you are on an open access point. (Otherwise, I totally agree with your answer!). – squircle Jul 2 '11 at 23:33
Thanks, but I know this. The trouble is, not everyone in my household knows this, nor, does every device support it. And, people on my network may use services other than Facebook (imagine that), many of which may not allow SSL. THIS VERY SITE, for example! – mkoistinen Jul 3 '11 at 8:20
But just putting a global password even on WPA2 still doesn't protect folks that don't use SSL. See How does FaceNiff work? - IT Security - Stack Exchange. – nealmcb Jul 3 '11 at 15:41
To be more clear, RE: @nealmcb's comment, using WPA2 will protect you against outside threats. But, if someone is given access to your Wi-Fi network, they can still capture your wireless traffic. – Iszi Jul 3 '11 at 16:19
@mkoistinen I know; it's not an answer to the question, that's why it's a comment. There's no need to freak out. All I am trying to point out is that, regardless of whether the AP is open or secured, it's best to use SSL/TLS wherever possible. That's why I left the note in parentheses at the end of my comment; I agree with your answer. :) – squircle Jul 3 '11 at 16:22

It is reasonably unsafe, but it really does depend on what you do. If you tunnel everything through SSH to some safe site or only stick to HTTPS you're reasonably safe (although you could still have someone come in and try to exploit machines on the network). Chances are you don't though, in which case you aren't very safe at all.

See this story for instance:

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Define "reasonably safe". Most people set up their home networks as a "trusted" connection, to make home network setups easier (so now you "trust" the attackers machine as well). Even if you did stick to HTTPS only, an attacker would still see where your internet traffic is traveling through, and the likelyhood of them obtaining relevant login information (or session IDs) through other unencrypted network traffic is almost always high. – Breakthrough Jul 2 '11 at 23:21

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