hi5, facebook, some of these are becoming target of hard headed hackers n cyberattackers so better not open any "video" content even if it is sent by any frend of yours...
reference:
http://tech.yahoo.com/news/nf/20090305/tc_nf/65095
reference:
http://tech.yahoo.com/news/nf/20090305/tc_nf/65095