What is the symbolic meaning of the vertical bar ( | )?

I have noticed that a lot of times, the symbol <3 (denoting a heart or the concept of love) is replaced by | automatically online (especially on facebook). I have also seen many people use the | (vertical bar or pipe) symbol to represent love or to signify a heart. WHY IS THIS? I don't know why or when this practice started. It's kind of driving me crazy, since I've searched everywhere for an explanation. Help, please?? Thanks in advance to whatever genius can answer this.