A jury in Texas has rulws that Apple must pay $626 million for infringing four patents held by VirnetX, a Nevada-based patent licensing company. The patents are related to technology used in Apple's VPN on Demand software back to 2009, its FaceTime messaging system back to 2010, and its iMessage software.

Three years ago, Apple was found to infringe on Virnet X patents and was ruled to pay a $368 million fine. Apple later managed to overturn the verdict on appeal.

On Wednesday, a jury in the Eastern District of Texas found that Apple's infringement was willful -- a legal finding that can greatly increase damages.

The Eastern District court is a popular place for patent infringement lawsuits and has earned a reputation as somewhere that favors patent holders in such disputes.

Virnet X has used courts in the district to go after other big tech firms in the past, suing them for infringement of its wide range of patents - in 2010, the company scored $200 million direct from Microsoft in an out-of-court settlement, and in 2014, it successfully sued for $23 million from Skype.