Q. 1. What is the position of the Catholic Church regarding the faithful receiving the Sacraments on the internet?
A. 1. The Catholic Church teaches that the Sacraments must be administered in person. As such, they cannot be administered electronically on the radio, television or the internet.
Q. 2. But I heard that there are some priests hearing confession on the internet. And what about if one misses Sunday Mass, can he not just watch it on television?
A. 2. Catholic priests in good standing do not administer the Sacrament of Confession over the internet. There are Protestant ministers who do so, their actions not being recognized as a valid Sacrament of the catholic Church. Anyone can allege to be a Catholic priest on the internet and deceive people into disclosing their sins. There is no way for a person to really know who they are talking to, confessing to, nor know if someone else is listening in on the conversation.
"Individual, integral confession and absolution remain the only ordinary way for the faithful to reconcile themselves with God and the Church, unless physical or moral impossibility excuses from this kind of confession." [OP 31] There are profound reasons for this. Christ is at work in each of the sacraments. He personally addresses every sinner: "My son, your sins are forgiven." [Mk 2:5] He is the physician tending each one of the sick who need him to cure them. [Cf. Mk 2:17] He raises them up and reintegrates them into fraternal communion. Personal confession is thus the form most expressive of reconciliation with God and with the Church." (Catechism of the Catholic Church # 1484)
"Individual and integral confession of grave sins followed by absolution remains the only ordinary means of reconciliation with God and with the Church." (Catechism of the Catholic Church # 1497)
"Individual and integral confession and absolution constitute the sole ordinary means by which a member of the faithful who is conscious of grave sin is reconciled with God and with the Church. ..." (Canon Law # 960)
Regarding the celebration of the Holy Mass, it is a great feast at which the faithful gather to celebrate the Sacrament of the Eucharist. By watching Holy Mass on the internet, the person is not gathering with the faithful, nor receiving the Sacrament of the Eucharist.
"The Sunday Eucharist (meaning "Holy Mass") is the foundation and confirmation of all Christian practice. For this reason the faithful are obliged to participate in the Eucharist on days of obligation, unless excused for a serious reason (for example, illness, the care of infants) or dispensed by their own pastor. [Canon Law # 1245] Those who deliberately fail in this obligation commit a grave sin." (C.C.C. # 2181)