[SpikeGronim]

How do you know if this caller is from the NSA for real? I could get up to all sorts if mischief. Either I can make the NSA look bad, or I can social engineer my way into ISPs by pretending to be the NSA. Good on this ISP though!

[cleverjake]

When I worked for a data center/ISP, there would be occasional government calls. The protocol was to get the persons name, then call them back through the official list of contact numbers (FBI, NSA, CIA, etc).

[TallGuyShort]

Also a good strategy when your bank / insurance agency, etc. calls

[sksksk]

There's an old scam that's been going round, where a person calls up a mark claiming to be from their bank.

They say that there are some security issues with their bank account and for security reasons, they should call the phone number on the back of their credit card.

The mark hangs the phone up, but the scammer stays on the line and plays a dial tone the line, when the mark picks the phone up, they hear a ring tone and then dial the number. The user thinks that they have got through to the bank, but really they are on the phone to the scammer.

From that point, they scammer has the mark's trust and can do all sorts of damage.

[jacquesm]

It's an interesting story but the phone system doesn't actually work that way.

[bcoates]

I haven't used a landline in years now, but when I was a kid it worked that way: one end hanging up wouldn't disconnect the circuit, and if the other end took the phone off-hook shortly afterwards it'd still be connected.

This would sometimes wind up being the deciding factor in the eternal battle of "which sibling gets to use the phone"

[lostlogin]

In my memory it never relied on both parties hanging up here in New Zealand, but on a trip to the UK as as child I noticed that the phone line disconnecting relied on both parties hanging up. I'm 31.

[manicdee]

On landlines the call isn't finished until the caller hangs up. This allows features such as "call waiting" to work: the receiver flashes the hook in a certain way to switch to the other call. If flashing the hook would disconnect the call, "call waiting" wouldn't work.

[mindcrime]

It did at one time, and could still in some places. I can recall growing up in rural North Carolina in the late 70's and early 80's, when one party staying on the line, after the other hand hung up, would keep the connection open.

[teh_klev]

In the UK it does. On a standard BT residential line the caller can hold the call open even after the callee has put down the handset. When the callee lifts the handset again they won't be able to begin a new call until the caller terminates the call.

[sksksk]

It does, at least in the UK

[ownagefool]

Are you sure about that? I live in Scotland and I think I'd have noticed not being able to hang up a call because the other side didn't.

[rosser]

Yep. The broad principle is never to give out account numbers, your social/government ID number, or any other such thing on a call you didn't initiate.

[runjake]

The NSA/CIA never (rarely?) call. Everything is (almost?) always routed through the FBI. If someone contacts you claiming to be from the CIA or NSA, and you are not employed by the DoD, they are very likely to be frauds.

From there, you can get the supposed agent's field office, look it up on fbi.gov and call them back.

http://www.fbi.gov/contact-us/field

Be advised that each field office has satellite offices within their jurisdictions. Satellite office addresses and phone numbers are published on fbi.gov also.

[lukashed]

I wonder how many would actually comply to such a call (before this whole PRISM thing came up) and how it would move on. I mean - why are they calling? Do they expect them to spell out their root passwords?