Silicon Valley shuttle buses have become a symbol of San Francisco’s gentrification anxiety – Facebook, eBay, Genentech, Yahoo, and most famously Google all have their own private bus lines shuttling workers in and out of the city, hiding them behind tinted glass and bathing them in free Wi-Fi so the riders can have a productive commute.

My home happens to be placed along one of Apple’s commuter bus lines, and the giant, silver buses have long felt like a constant presence on the residential street, powering up and down the hill, plowing past my window, honking a polite warning as they pass while I double-park to unload groceries. Apple workers have seen me in pajamas, stepping outside to get the paper or throw a dirty diaper in the trash. They’ve seen me chasing my kids into the car for the morning for the ride to school. In the evening the Apple Bus sometimes sees me waiting in my car for it to pass, so I can open the door without losing it to the bus’s grill.

Last week, it occurred to me that I might start monitoring the local Wi-Fi environment to determine how often the Apple Bus really comes by. My wife guessed 10 times a day. I’d have said 20.

After a week of reverse-wardriving, it appears the Apple Bus passes my house an average of 36 times a day, and is uncannily punctual, especially in the a.m., when the first bus reliably pops up on my Wi-Fi radar between 6:23:33 and 6:23:56 every morning.

The second bus passes four or five minutes later, the third 25-minutes after that, another at 6:58, give or take a minute. By 10 a.m. as many as 15 more Apple buses have passed. After that they become infrequent, and die out entirely a few minutes after 2:00 p.m., before they return in force at 5:00 p.m. – presumably taking Apple workers home. The last bus registers at about 10:15 at night.

On Monday, the busiest day, 21 buses pass before noon, 20 after. Based on the MAC addresses, I’ve seen 49 different physical buses in a week. The trusty B4:C7:99:DF:72:10 is the most frequent on my route, popping up 16 times during the week.

Apple isn’t the only one. I also catch an eBay bus at 8:10 a.m., returning at 6:22 p.m., and I’ve seen the Google Bus twice.

The tech commuter buses have come under heavy fire recently, seen as the embodiment of skyrocketing rental prices and other tech-boom gentrification woes. Demonstrators waving signs have encircled and blocked Google and Apple buses. In July, a pilot program enacted by San Francisco’s transportation authority will start forcing the companies to document their buses and routes, and pay $1 every time they use a city bus stop.

These buses are huge, intimidating, Greyhound-sized affairs, many of them double-deckers, that feel outsized on a relatively quiet street of single-family homes. I haven’t stockpiled much umbrage over them, but some of my neighbors who’ve lived here longer hate the buses. There’s something disconcerting about having your street turn into a major artery in the transportation infrastructure of a company 45 miles away, without so much as a mailer (“Hi! We’re Apple. We’ll be using your street for a while.”).

In fact, among the commuter buses, Apple’s are particularly stealthy and anonymous. There’s not a mark on them that indicates they’re Apple’s. They might well be commuting to Area 51. Even their Wi-Fi is stealthy. eBay broadcasts as “eBay Bus.” Google as “GBUS”. Apple? “CommuteWiFi”.

I know it’s Apple, because there are unofficial maps in circulation that show which companies are operating on which streets – my house is squarely on one of Apple’s routes. As supporting evidence, I picked up three of the riders on the unmarked buses who tethered their iPhones, which turns them into mobile Wi-Fi hotspots that broadcast the full name of the employee in the SSID. A LinkedIn search verifies they’re on their way to Cupertino. Hi Bart! Hi Craig! Hi Marco! Good to see you. Please don’t mind the pajamas.