[PunchTunnel]

It also might be (as it proved in my case) that your address block (including the whole neighborhood from an ISP perspective) includes a compromised device. I discovered one of my neighbors has a compromised device that's sending a couple million spam emails per month, and it tainted the reputation of the entire network address block.

[jordanb]

Well it happens on both my laptop and my phone, both of which are firefox with a lot of the fingerprinting stuff like useragent knocked out, as well as adblock, etc.