What kind of person tells another what "we" are talking about?
Who says you were included in "we?" "We" stands for the people who are on the other side of the argument from you. If you disagree with me, don't include yourself in "we."
I really am talking about searching for specific individuals
And the reason I address that the way I do is because IT IS NOT HOW CRIMINALS OPERATE.
Do you want to know who DOES look for specific people? Employers you've applied to, police investigators, friends of yours, and most notably not the people who are going to misuse your personal information. 99.9% of the time, any person who is looking for information specifically about you is someone you know, and, as has already been stated, if you want to legislate based the on the incredibly unlikely and ultimately unpreventable we will have no freedoms left, corporate or personal.
For proper illustration of this point, consider that 0.1% of the time, a Tuba might be used as a murder weapon. Clearly we should outlaw tubas.
2% of the time someone is stabbed by a steak knife. All public silverware should be plastic. Oh, wait, I'm sorry: plastic can be sharp too. Use your hands.
Arsonists use lighters or matches to start fires frequently. Clearly they should be outlawed.
You (and yes, I mean you) are talking about outlawing a Tool which has numerous legitimate uses because a few nutjobs might misuse it. My (and this does not include you) point is that these nutjobs are going to do what they were going to do with or without that tool; so, if it's useful, why get rid of the tool?
The Data Protection Act regulates the collection and storage of personally identifiable information
Which I am 93.7% positive includes neither your MAC Address nor the geolocation of your wifi network.
In particular, there is a requirement to keep such data securely - publishing it on the internet hardly fits the bill does it?
Right, it doesn't, but Google isn't publishing personally identifiable information. It gives you the geolocation of a wifi network, probably the point at which the street view car identified the network (in the middle of the street) within a range of ~9 meters (or 27 feet). So, if you're the only person within 27 feet of a point on the street with a router, it could technically be personally identifiable, except you still have that one-to-many relationship between routers (one) and people (many)
That's not personally identifiable information.
And you still haven't answered the question as to why anyone would be seeking you out. Or that police officer. Or that soldier (for the record, that Muslim terrorist would probably be just as happy to blow up a bus full of civilians as a bus full of soldiers).