Ruling on prisoners praying Jumu’ah when they are in their cells

The Committee of Senior Scholars issued a fatwa stating
that they did not agree with prisoners praying Jumu’ah or in congregation
behind one imaam in Jumu’ah or congregational prayers, and following
him via loudspeakers whilst they are in their prison cells, because
they are not obliged to pray Jumu’ah since they cannot go to the prayer,
and for other reasons. 

But anyone who is able to attend Jumu’ah prayers in the
prison mosque – if there is a mosque there – should pray it in congregation.
Otherwise a person is not obliged to pray Jumu’ah and he should pray
Zuhr instead. The group in each cell should pray the five daily prayers
in congregation inside their cell if it is not possible for them to
gather in the mosque or in one place.