Those that are blocked -LRB- again , primarily schools -RRB- , are commonly blocked repeatedly and for long periods -LRB- up to a year at a time -RRB- for blatant vandalism .

Those that are blocked -LRB- again , mostly schools -RRB- , are commonly blocked repeatedly and for long periods -LRB- up to a year at a time -RRB- for vandalism .
