From the Fatwas of Grand (not really) Ayatollah Sistani:
Question 1: What is Islam's opinion on love, i.e. the love of a boy for a girl?
Answer: If it brought in the impermissible or the fear of it, then it is not permissible.
Question 2: What is the ruling on noble love that aims toward marriage no more?
Answer: No love shall be shown for a foreign woman, and vice versa, because it will often lead to the impermissible, and practicing of love is also impermissible.
Question 3: Is demonstrating love without purpose and without the goal of lust allowed?
Answer: It is not permissible to demonstrate love for fear of falling in the impermissible even if gradually.
Question 5: What is your opinion in forming relationships or friendships or love between a man and a woman through the internet?
Answer: It is not permissible because not falling in the impermissible is not guaranteed, even if gradually.