There was an ethernet cable plugged into the inverter panel, which ran to a Comcast box.
We switched to FIOS after a couple of months, and never switched the connectivity of the solar panels. Everything worked fine, but ...
A few months later, I received a strongly worded email from an organization I had never heard of, saying that I needed to get the solar panels back online, because it was a requirement of the contract the previous owner had entered into to sell the SRECs generated by the panels. Failing to connect the panels to the Internet could lead them to pursue action related to a lien they had on our property.
Wait, what contract? And what lien? This was the first I'd heard of either, and the lien hadn't come up during the title-insurance process.
It turns out the previous owner of the house had entered into a contract with an organization in our state that pays you a lump sum, if you sign away the rights to the SRECs your system generates. The owner had used that lump sum to help pay for the panels.
But then he sold the house to my wife and me, without ever disclosing the existence of the contract. So basically he sold the SRECs to both of us. He sold them to the organization by virtue of their contract, and he sold them to us, by virtue of the ownership of the panels transferring to us when we bought the house.
And the lien never came up because it was not against the real estate itself; rather, it was against the SRECs -- the Solar Renewable Energy Credits that are generated by the panels. They're not physical assets, but they do have substantial value.
It took the retention of a lawyer and a whole bunch of back-and-forth between us, the seller, our buyer and seller's agents, the lawyer who handled our settlement, and the SREC-buying organization to get the whole mess sorted out.
In the end, we got the lien and contract dissolved ... and then we hooked the panels up to FIOS, and I get handy little charts of all the SRECs we're generating :)