Lots and lots. A particular interest of mine is churches, and Google
takes the correspondence address of a church as its location. However,
post is probably addressed to the minister, who doesn't usually live
in the church. The end result is that the church icon on the map is
located close to the vicarage instead of the church.
There are certainly others. And inconsistencies in which icons are
displayed -- why one hotel in particular and not another, for example?
Including POI data has not been an unmitigated success. Read that with
British understatement switched on.