Etymology

One of my interests is Etymology.  That is the study of the derivation and history of words.  I have recently come across a strange phrase “Internet Troll”.  My research has revealed that the word troll has two definitions associated with it.  

The first is a mythical creature from Norse mythology that dwells in rocks and isolated places and is malevolent to human beings

The other definition.  To troll, is act of towing a bright flashy lure behind a boat in order to capture its prey.  

I really can’t decide which of these definitions is the source of Troll in the Internet context.   I just wonder if anyone or group of individuals who contribute on here and I am sure have much greater knowledge than me could enlighten me with regards to the derivation of this phrase?

Thanks in advance.