Guild Wars 2

Is there someway of reporting this? We have 2 people on our server that are obviously working for some other server. They build an enormous amount of useless siege, exhausting both the siege cap and any supplies in the towers/keeps, etc.

Apparently this has been going on for some time and not just on our server. We have plenty of screen shots and the names of the 2 people involved. Is there any recourse for this? Makes the WvW a lot less fun.

Take pictures.
Submit to: https://en.support.guildwars2.com/app/ask/

Choose violation: than griefing.