Editing Denial-of-service attack (section)

===Telephony denial-of-service===
[[Voice over IP]] has made abusive origination of large numbers of [[telephone]] voice calls inexpensive and easily automated while permitting call origins to be misrepresented through [[caller ID spoofing]]. According to the US [[Federal Bureau of Investigation]], telephony denial-of-service (TDoS) has appeared as part of various fraudulent schemes:
* A scammer contacts the victim's banker or broker, impersonating the victim to request a funds transfer. The banker's attempt to contact the victim for verification of the transfer fails as the victim's telephone lines are being flooded with bogus calls, rendering the victim unreachable.<ref>{{cite web|url=https://www.fbi.gov/newark/press-releases/2010/nk051110.htm |title=FBI — Phony Phone Calls Distract Consumers from Genuine Theft |publisher=FBI.gov |date=2010-05-11 |access-date=2013-09-10}}</ref>
* A scammer contacts consumers with a bogus claim to collect an outstanding [[payday loan]] for thousands of dollars. When the consumer objects, the scammer retaliates by flooding the victim's employer with automated calls. In some cases, the displayed caller ID is spoofed to impersonate police or law enforcement agencies.<ref>{{cite web|url=http://www.ic3.gov/media/2013/130107.aspx |title= Internet Crime Complaint Center's (IC3) Scam Alerts January 7, 2013 |work=IC3.gov |date=2013-01-07 |access-date=2013-09-10}}</ref>
* [[Swatting]]: A scammer contacts consumers with a bogus debt collection demand and threatens to send police; when the victim balks, the scammer floods local police numbers with calls on which caller ID is spoofed to display the victim's number. Police soon arrive at the victim's residence attempting to find the origin of the calls.

TDoS can exist even without [[Internet telephony]]. In the [[2002 New Hampshire Senate election phone jamming scandal]], [[telemarketing|telemarketers]] were used to flood political opponents with spurious calls to jam phone banks on election day. Widespread publication of a number can also flood it with enough calls to render it unusable, as happened by accident in 1981 with multiple +1-[[area code]]-867-5309 subscribers inundated by hundreds of calls daily in response to the song "[[867-5309/Jenny]]". TDoS differs from other [[telephone harassment]] (such as [[prank call]]s and [[obscene phone call]]s) by the number of calls originated. By occupying lines continuously with repeated automated calls, the victim is prevented from making or receiving both routine and emergency telephone calls. Related exploits include SMS flooding attacks and [[black fax]] or continuous fax transmission by using a loop of paper at the sender.