How paranoid are we?

Seriously, you might decide, after shopping the big-box store shelves clogged with home security cameras.

Not long ago, snoop cams were mostly the province of such specialty companies as Swann that market hard-wired, CCTV (closed-circuit television) cameras and time-lapse video recorders to shopkeepers and large estate owners. (A four- to eight-camera Swann system goes for $160 to $700, plus display screen and installation.)

Then Motorola and Fisher Price made 'em an every-family product, re-fashioning the cameras as wireless baby-cams (with companion monitors) to watch over our precious little ones.

Today, lots of companies - from computer-accessory specialists D-Link and Netgear to such megapowers as Google, Samsung, and Panasonic - are pitching more sophisticated WiFi-linked and Web-broadcasting cameras as "peace of mind" providers.

"Seventy to 80 percent of our customers use them as an alternative to a traditional home-security solution," said Ken Lloyd of D-Link. Just mounting them in obvious places "offers a level of deterrent. Then you get instant alerts and the ability to see what's going on, as the camera detects and reports any movement at your location."

Beaming images and sound over the Internet to your smartphone, tablet, or computer, these security cameras also offer positive affirmations: Your kid has arrived home safely. The snow hasn't caved in the roof of your vacation cabin. The new puppy isn't chewing on the table legs. Or, if he is, you can remotely turn on the camera's speaker and shout "get away from there!" Or, with a specialized "pet cam" (see below), offer a better distraction.

Tech nerds will appreciate how fine-tunable today's security cameras are with special computer software. Say, to ignore the swaying tree branches visible through a window, which can set off a "false positive" alarm. Or to set up multiple alert contacts.

For today's test, we've gone hands-on with security cams that require only a smartphone or tablet app (no computer!) and a bit of set-up patience. All balked some, before connecting to my WiFi network.

Nest Cam. Google-backed Nest Cam ($200) earns high praise for its ultra-wide-angle "fish-eye" lens, excellent clarity (even with digital zooming), and low light sensitivity, plus unique interaction with Nest Protect fire detectors and other items such as Ooma Internet phones. And how "E.T." cute is it?

Downsides: A Nest Cam runs hot. Talk-back speaker quality is lousy. And the cloud-based recording (which saves the last 10 days of video) costs $100 a year for the first Nest Cam, $50 for each additional.

D-Link Pan and Tilt Day/Night Network Cloud Camera (DCS-5020L. $90 to $120): This robotic, 720p camera has eyes in the back of its head. At your command, it rotates 340 degrees, and also tilts up and down (120 degrees), capturing almost everything in sight from ceiling to floor. This D-Link also acts as a WiFi extender, good for "daisy chaining" multiple cameras.

Downsides: not very sharp or sensitive in low light, often downshifting into black-and-white mode. Doesn't enable free local recording, available on several other D-Link models.

Simplicam. This tidy product's $200 price includes a year of cloud-based, one-day recording to help catch a thief. Offers superior motion-detection tuning. Downside: Face-detection software, while rare, is also poorly executed.

Netgear Arlo.Designed for indoor or outdoor use, this HD camera system is weatherproof and entirely "wire-free" (other WiFi wireless security-cam systems above still require AC power connections). Love the magnetic camera mounts and the free cloud backup system, saving seven days of recordings.

Downside: Don't mount an Arlo too far out of reach, as you'll be trading out the battery (CR123A type) every four to six months; $499 buys a four-camera system.

Petzi Treat Cam. Absentee animal owners can get over their guilt with this clever box camera ($169). Doesn't just let you observe, take pictures, and talk with your pet from afar (speaker quality is the best of the bunch). Also dispenses a sprinkling of dog or cat treats after a tap on your mobile-phone screen.

Downside: Opening/reloading the treat dispenser is tricky. And your now-Pavlovian-trained animal may never leave the spot.

PetCube. Modern cubist design ($199) disguises its true nature. Wide-angle lens is angled down for four-legged friends. From your distant touch screen, you can point and wiggle a red laser beam for the cat or dog to chase, encouraging exercise. Or interact with others' PetCube pals.

Downsides: Just one of my (two) felines liked chasing the light. And while the laser is low powered, a cautionary label warns that staring into the light is still a no-no. Hard to explain that to an animal.