Help!

I don't know what happened.  But I guess, it all started when I linked my Facebook account to my yahoo account just a few weeks ago.  I was glad I did that because now, I get to check FB updates straight from my Yahoo account.  On the other hand, long before that, I had my mobile no. registered thru yahoo messenger so that, even when I am offline, I can still receive and retrieve messages from my cellphone.

However, I first noticed that something went wrong when i was awaken by a message alarm from my cellphone at around 4 o'clock in the morning.  It was from a classmate asking me, "Gising ka pa?" (Still awake?).  What a question... I was awaken just to be asked if I'm still awake? Hahaha!  I reread the message again and to my horror, she texted thru FB!  And it was not only from her that I got FB messages at wee hours of the morning... at DIFFERENT days.

Few days ago, another classmate teased me that he always see me online at FB.  Not only that, hubby commented that I was online in Yahoo when I was supposed to be mobile.  I swear, I signed out of my account PROPERLY.  This incident happened a number of times already, that's why I am little bit bothered.

It only means one thing:  I have been online ALL the time.  Why?  What have I done? Will somebody explain what's going on?