I am in the Underground Construction Business(15yrs.) That is an easement for utlility lines and such. They have every right to be there. With your permission or without it. If you choose to not let them in your yard They have the right to Call the Police and then they will be let in to your yard. And probaly will not be very careful then not to mess things up.
The only thing you have a right to have in the easement is grass. They do not have to replace trees/landscaping, structures/ concrete, etc. Most including Us try our VERY BEST to treat your property with Respect and Leave it how we found it. In most cases our crew puts a yard back together so well, that you can hardly even tell we were there. Most Homeowners are very pleased when we leave. We make a point to ask them if all is ok. And if it is not we try to please them if possible. They are bringing new technology to you and your neighbors faster internet better TV. Be respectful let them do their job and they will respect you also.