And many here keep saying the mosque is private property. Who owns it? Specifically who has an ownership interest and who does not? I doubt anyone here knows that, or whether Muslims have formal membership requirements, and whether these members were members.
Really, it's not that complicated, which leads me to believe you're being argumentative.
Who owns it? The corporation, partnership or sole propriety that is the religious enterprise owns it. There are officers of that corporation and those officers or designees, enjoy the rights that any private property owner enjoys.
If you walk into a church and the parish priest or his designee tells you to leave and you don't leave, you're trespassing. It's not that complicated.