Q: When I'm at home, my cellphone and laptop access the Internet through a Verizon Wireless MiFi unit (a cellular device that broadcasts a Wi-Fi signal). I use the MiFi for accessing e-mail, Facebook, Instagram and the Pandora streaming music service. I leave it on all the time because it has security software.
But, 12 days into my monthly billing cycle, I was surprised that I'd used 75 percent of my 10 gigabyte monthly data plan, nearly all of it through my phone. A short time later, I had used 90 percent, and minutes later I went over the data limit. This had never occurred before.
I immediately upgraded my wireless data plan to 18 gigabytes to avoid charges for going over my limit. But by the next morning, I'd gone over the 18-gigabyte limit, even though I hadn't used my phone or laptop all night. What happened?
Dan Rusch, Tonka Bay
A: Pandora, your most data-intensive Internet activity, uses only about 1 gigabyte of data in 20 hours of use and couldn't possibly drain your data plan overnight. That probably means your MiFi unit has been hacked, and that its Wi-Fi is being used by someone nearby — maybe sitting in a car across the street — to e-mail many gigabytes worth of spam or malicious software through your Verizon account. All that data traffic has used up your monthly data allotment in a matter of hours.
How could that happen? There have been reports of consumers incurring overuse charges for huge amounts of data, apparently because they hadn't changed the MiFi device's easily guessed default password (see tinyurl.com/ouwo9gz). In addition, computer professionals have found that the MiFi's default encryption protection is easily breached (see tinyurl.com/pqvy34v).
To protect yourself, change the MiFi unit's password and encryption key (to locate them, see verizonwireless.com/support/knowledge-base-43966/or ask Verizon Wireless).
Q: I need to put 50 short videos that take up a total of 3.5 hours on a high-capacity double-recording-layer DVD disk. I also need to create a menu with "chapters" for the disk. What software should I use? In addition, how can I be sure that my DVD drive, called a "DVD MultiRecorder/DVD + R DL" can handle the task?
Dayle Vickery, Orange Park, Fla.
A: You can find a list of free video burning programs for Windows 10 (and other versions of Windows) at tinyurl.com/oc74hcd (note which ones enable you to create chapters). In addition, there's a list of free and for-pay video burning programs at tinyurl.com/norr5no.
Your DVD burner should be able to record the videos. The "DL" in its name stands for "double-layer" recording. But be sure to buy disks labeled "+ R DL." An ordinary DVD player should be able to play the disk.
E-mail tech questions to email@example.com or write to Tech Q&A, 650 3rd Av. S., Suite 1300, Minneapolis, MN 55488. Include name, city and telephone number.