LCDs aren't as susceptible to permanent ghosting or "burn-in" unlike plasma and OLED panels.
However, they are prone to a similar, albeit temporary condition called image retention.
It doesn't happen all the time but when displaying a static image for extended periods, the constant voltage may cause the liquid crystal to "stick", causing the effect. The solution is to either shut the display off or display a white image until the liquid crystals "unstick".
Image retention should not occur frequently, so if it does, the panel may be defective.