Current Legal Issues
Of course, whomsoever knew of a private property that was forcibly owned by the government, without having the landlords’ consent by way of compensation or the like, the rules regarding usurped land apply. In this case, it is not permissible to use such a site, even walk in it, without prior consent of the original owners or their guardian, from their immediate relatives - e.g. father, grandfather - or anyone appointed by them. If the owner is unknown, it should be treated as majhoulil malik, where the advice of the Marji’ should be sought. The same ruling applies to the remnants of property, in that it is not permissible to have free hand in them, except with the permission of their owners.
As for lands belonging to schools and the like, there is ishkal in the permissibility of having the same access [as in mosques, cemeteries and Hussainiyyas discussed above], except for those purposes and persons stipulated in the endowment deed.
As for the remnants [ruins] thereof, if they are not outside the pale of what is generally accepted as a mosque, the rules governing the mosques should still carry weight. In case it is no longer what you can term as mosque, for example they were turned into shops, houses, etc. by the oppressor (adh-Dhalim), the rules in question do not apply to them. It is, therefore, permissible to use them, in any manner lawful, except that which perpetuates the state of them being maghsoub; it is not permissible.
If what was left of the mosque’s fixtures were originally of its own property, since they (in kind) were bought for the sole use of the mosque by way of endowment deed, it is not obligatory to use them (in kind) in another mosque. Rather, it is permissible for the guardian or any authorised person, as they deem fit, to sell them and spend the proceeds on another mosque.
The rules that have been discussed here should apply to the fixtures of schools, Hussainiyyas and other public places, previously occupying sites that were later used to build roads on.
If they were neither private property nor public endowment, there is no harm in making use of them, provided the act does not constitute desecration.
The same goes for the remnants of land thereof. That is, on the first assumption, it is not permissible to dispose of it or sell it, except with the permission of their owner. On the second assumption, it is not permissible, except with the permission of the guardian or whoever in his capacity. The proceeds of sale should be spent on other Muslim cemeteries, taking into account the intimate closeness of relatives as first priority, as a matter of ihtiyat.
On the third assumption, it is permissible without the permission of anyone, except where it does not amount to having free hand in other people’s property, such as the sites of demolished graves.