Trend Labs shares an important holiday warning to be cautious in selecting any link, app, or theme:

FaceBook – Valentines Malware themes circulating
http://blog.trendmicro.com/facebook-valentines-theme-leads-to-malware/

QUOTE:  It’s never too early to get ready for Valentine’s day, it seems, even when it comes to malicious attacks. Recently, I came across a scam in Facebook that leverages the upcoming occasion.   The said attack begins with a post on affected users’ wall inviting other users to install a Valentine’s theme into their Facebook profile