In 2008, a network monitoring technology known as deep packet inspection gained notoriety as a few companies began using it to target Internet advertising. Deep packet inspection looks into the contents of Web page requests, emails, and other traffic generated by Internet users to identify the specific content an individual is browsing or sharing online. Because the inspection process typically happens without the users' knowledge, some consider it an egregious invasion of privacy. Public furor generally prevented the technology from becoming too widespread before.

Now it seems deep packet inspection is making a comeback, as a few advertising-related firms are again in the news for attempts to enable it on certain Internet Service Provider (ISP) networks. Will it succeed this time?

→ More - Shunned Profiling Technology on Verge of Comeback
→ More - U.S. Lawmakers Target Deep Packet Inspection in Privacy Bill (2009)
→ See also - Is Your ISP Spying on You? (2008)

A hotspot gateway is a type of wireless access point specially designed to regulate access to the Internet. Hotspot gateways are commonly used by small businesses providing Internet service on a subscription basis. They allow an administrator to set up individual logins, monitor usage per account, and better protect a hotspot from outside attackers.
→ See also - Stealing From or Sharing Wi-Fi Access with Neighbors

A port scan is a methodical attempt to gain unauthorized access to a computer network. Port scans, usually done with sophisticated software utilities, send messages to individual TCP or UDP ports on a network gateway device. A port scan attempts to identify specific port numbers on the gateway that may be unsecured and thus open to further probing and possible network attack.
→ More - Introduction to Port Scanning (netsecurity.about.com)
→ See also - Can Port Scans Damage Network Switches?

Since its general availability in October, the Firesheep Firefox extension has gained much notoriety for its ability to expose users on public Wi-Fi networks. By downloading and installing this simple extension, users who don't know much about wireless networks can easily snoop on the user names and passwords others use to log in to many popular Web sites. (Though Facebook and Twitter are two of the best-known examples, Firesheep is not restricted to spying on users of those two sites only.)

While various countermeasures exist, two of the simplest available are other Firefox extensions designed to defend, or counter-attack Firesheep, respectively. Installing either or both of these will help keep Firesheep at bay on any public Wi-Fi networks you use:

• BlackSheep (zscaler.com)
  
• FireShepherd (hi.is)

→ More - Firesheep (antivirus.about.com)