"In case they win, Van Der Meer’s heirs, and the anonymous owner of Rembrandt IP can claim monopoly rights to an “online diary” until 2021."

ArsTechnica explains:

Facebook didn't pop up on the scene until 2003, but "it bears a remarkable resemblance, both in terms of its functionality and technical implementation, to the personal web page diary that Van Der Meer had invented years earlier," the complaint states. Facebook lets its users arrange personal information, as well as third-party content, in a chronological format; it allows the user to share "specific diary entries with a selected group of people, such as the user's friends, through the use of user-settable privacy levels." And Facebook is powered by advertising revenue, a business model that's specifically described in the '316 patent.

...

Rembrandt is also a very successful patent-holding company; it was founded in 2004 and by 2008 had raised over $150 million to pursue patents it thought looked like good investments. That allowed it to wrest a $41 million verdict from contact-lens maker Ciba Vision in 2008. That same year, Rembrandt claimed to have patent rights to both the digital-TV standard and the DOCSIS cable-modem standard, and it was accused of pretending to be in the cable-modem business itself in order to gain leverage in that case. 

A lot of the features they're claiming we're available in LiveJournal, available in 2000.

Which makes it hard to believe Rembrandt was wronged.

Still, this is IP Law, so that has nothing o do with it.