One of the most successful digital technologies of the past decade has been Wi-Fi. From home networks and college campuses to coffee shops and airports, Wi-Fi is a convenient and inexpensive way to connect multiple PCs, smartphones, tablet computers, game consoles, and other digital devices to the Internet.

Wi-Fi, which stands for wireless fidelity, is the name of an increasingly popular wireless networking technology based on radio waves. Instead of communicating through a cable, devices connect over the air.

These days most digital portable devices have Wi-Fi adapters built in. You can buy inexpensive Wi-Fi adapters for desktop PCs as well as many newer televisions. With Wi-Fi enabled TVs, you can watch videos, movies, and shows from www.YouTube.com and www.Hulu.com for free and movies and shows from www.Netflix.com inexpensively.

More and more "hotspots" allow for free (and sometimes pay) Wi-Fi access to the Internet. According to a new study by market research firm In-Stat (www.in-stat.com), the number of Wi-Fi hotspot locales is expected to increase to one million by 2013.

The In-Stat report also indicates that although transportation and convention centers make up a small percentage of total hotspots, they account for nearly 30% of the total connects, indicating heavy usage.

Besides the usual locales, hotspots are also found at military bases, hospitals, gas stations, department stores, supermarkets, and RV parks and campgrounds.

Notebook computers continue to account for the majority of connects at hotspots today, according to In-Stat, but the use of smartphones and tablet computers is increasing rapidly.

Wi-Fi access to the Internet isn't without its risks and problems. At the top of the list is security. Accessing the Internet at a free public hotspot, in a worst-case scenario, can allow identity thieves to steal your Social Security number, bank log-in name and password, and other personal information.

One trick is for crooks to set up a rogue Wi-Fi network that looks just like the legitimate one of the library or coffee shop you're visiting but that lets crooks see and harvest the information they need to steal from you.

How to avoid this?

If you're at a hotspot that doesn't require a password, assume that whatever you type in can be read by someone else, not that it will, but that it can. It only makes sense then to avoid doing online banking, paying for something you buy through PayPal, or anything else that's sensitive.

If you have to type in a password, and you have a choice between a WEP or WPA/WPA2-type passkey, chose the newer and more secure WPA or WPA2. WEP can easily be cracked, so avoid communicating anything sensitive here too if possible.

Even if you have access to WPA2 encryption, your data is secure only to those who aren't accessing the Internet from the same hotspot. A snoop two seats over using wireless packet analyzer software may be able to see what you type.

To prevent this, stick with Web software that uses HTTPS security, such as Gmail and Google Apps or your corporate Webmail system if you have one. Similarly, type in “https:” to access Web sites such as Twitter, Facebook, and any others that permit it.

If you're traveling on business and your company offers a secure virtual private network (VPN), use that at a public hotspot. If you don't have access to one, another option is to sign up for a free VPN service such as Hotspot Shield from AnchorFree (www.anchorfree.com). You download and install the software before you use a public hotspot.

Home Wi-Fi networks also present security and other challenges. Many people don't turn on security when setting up a home Wi-Fi network, which can enable a neighbor to capture your personal information as well as freeload off your Internet connection.

Securing your home Wi-Fi simply requires using a software program and typing in the passkey whenever you add a new device to the network. Another trick sometimes recommended is choosing an intimidating network name (SSID) such as c:\virus.exe to scare off nosy neighbors. Alternately, you can disable SSID broadcasting, which hides your network's name.

The usable distance inside for a Wi-Fi signal is typically 50 to 100 feet. Brick or concrete walls can reduce signal strength. Large apartment complexes can be subjected to "Wi-Fi pollution," degrading the connection, if there are too many users in a concentrated area. 

Finally, some household electronics such as cordless phones and baby monitors can interfere with a Wi-Fi signal. Look for those that don't use the 2.4GHz or 5.8GHz bands.