5mins is considered close. Seems they think that you are on their land and want to get you out from there. If they went as far as making claims around your place then you should be extra carefull when you meet em. I'm sure they'll try to kill you.
You can declaim their claims but for that you need to have village(town bell:some metal + writ for 2500silver needed). When village claim covers their claim stones you can revoke their claims with new command you'll get in menus. Revoking claim costs 2x claim size in tiles.
As for trespassing those claims: you are leaving clue each time you pass that claim but that's unsummonable 'crime'. As long as you won't try to steal anything from that place/destroy anything in there you are safe. Be sure not to logout when you see them coming and when you have 'crime' debuff(lasts 15mins after commiting crime(even trespassing!)). With 'crime' debuff your char stays online for duration of said crime debuff even after you logout.
PS. You can try to find yourself on world map (
http://ad.lylay.com/hts/smap.html)and ask for some help(just be sure not to post coords in public so other griefers won't come to you).Would be cool if 'criminals' left some clues on your property(especially summonable ones). Try toggling 'tracking on' in adventure menu, teleport to boston and back to your place then look for pinkish '!' signs hovering above the ground. If some of those (after collecting) will give you evidence..That's great. You can hire/look for someone to take care of your troublemakers