A free service launched on Wednesday called PrivateSky lets Internet users shield email, Facebook updates, and other online exchanges from hackers or other unwanted snoops.

The service from startup CertiVox comes as hackers appear to be rampaging through the Internet, cracking defenses at companies, attacking public websites, and tricking their way into email accounts to spy on contents.

PrivateSky works with Internet Explorer (IE) browsers to provide encryption for whatever people type into message boxes and decodes it only for those they chose.

Users highlight blog posts, Facebook updates, email messages or other text then indicate who should be allowed to read them. Missives are decrypted only for intended recipients.

"It is literally one click encryption and decryption," said CertiVox founder and chief executive Brian Spector.

Internet security firm Trend Micro warned this month that cyberattackers have attempted to infiltrate Web-based email services run by Microsoft and Yahoo! as well as Google.

"There has been a variety of recent attacks on popular Webmail platforms," Trend Micro senior threat researcher Nart Villeneuve said in an online post. "In addition to Gmail, Hotmail and Yahoo! Mail have also been targeted."

Trend Micro released the news after Google said a cyber spying campaign originating in China had targeted Gmail accounts of US officials, military personnel, journalists, Chinese political activists, and officials in several Asian countries, mainly in South Korea.

Encrypting email is seen as a way to thwart email snooping, but the process has typically taken a bit of software savvy.

CertiVox set out to make encryption simple with PrivateSky. "This is kind of like arming the citizenry," Spector said.

The encryption service works on any Web-based email such as Gmail, Hotmail or Yahoo! Mail as well as posts at social networks.

CertiVox started with IE because of its global popularity but is adapting the service to other Web browsing software. CertiVox intends to eventually encrypt photos and other large data files as well as text.

The application for IE browsers is available for download online at https://privatesky.me.