LINKEDIN, the world's most popular professional networking website, is being sued by customers who claim the company hacked into their private email accounts for marketing purposes.
A group of US customers have alleged that the company broke into their email accounts to access their contact lists.
They said LinkedIn required them to provide an external email address as their username on its site, then used that information to access their external email accounts when they were left open.
They have asked a federal judge in California to bar the company from repeating the alleged violations and to force it to return any money generated by its use of their identities to promote the site to non-members, according to a court filing.
"LinkedIn's own website contains hundreds of complaints regarding this practice," they said in the complaint, which also seeks unspecified damages.
"The appropriation of email addresses to send multiple reminder emails promoting its service is motivated by monetary gain," they added.
LinkedIn user Deborah Lagutaris said the site contacted more than 3,000 people in her name, including those copied in on her email messages.
"This means that not only direct email contacts but peripherals as well" were used, she said.
"I contacted LinkedIn and they said, 'Oh, you can remove all those invitations from your account manually. We don't know what happened'."
A LinkedIn spokesperson said the lawsuit was without merit and the company would fight it.
"We never send messages or invitations to join LinkedIn on your behalf to anyone unless you have given us permission to do so," said another.
LinkedIn claims to have the largest online professional network in the world with more than 238 million members.