11 In this manner the civil power prepared the way to render even the precarious use of her property impossible to the Catholic Church. Since she is deprived of everything - deprived of every subsidy, and hindered in all her activities - how can she pay these taxes? Nor can one say that under the law the Catholic Church has the faculty to own at least some private property, because even the reduced right is almost nullified by a principle soon afterward enunciated, that those properties may only be held in the quantity necessary for religious services. In this way the Church is compelled to submit to examination by the civil power for the fulfillment of her divine mission, and the State has constituted itself judge of what is necessary for purely spiritual functions. Therefore, there is reason to fear such judgment as being in accordance with the laic intentions of the laws and their authors.
Source: Dilectissima Nobis (Vatican.va)