The following question was put to a marja`:
What is the ruling on conducting a marriage when the matter and ceremony take place over the internet or by way of telephone?
The answer from the marja`, Imam Wahbah Az-Zuhayli, may Allah preserve him, is as follows:
A marriage conducted by these means is not valid due to the unsecure nature of the obtaining of witnesses, that all have answered, agreed and accepted the terms of the marriage. Based on this, it is not valid.
 Fatawa Ma`asirah, pp. 227-228, Dar ul-Fikr, Damascus, 1424 AH