Phorm in a tea cup?
If you walk down the street and pop into a sex shop in broad daylight, you run the risk of being seen. So, you get yourself a dirty macintosh and turn your collar up and protect your privacy.
If you pop into a sex site on the Internet, it is a similar deal. You risk being seen. So you get yourself something to conceal your activities, if you are concerned about your privacy... if it makes you less electable as a member of Parliament.
Your ISP and therefore Phorm can't snoop SSL (HTTPS). If you read your mail over SSL, your mail is private. Charity Worker, make sure you read your mail over HTTPS. If you browse information that you do not want others to know about or associate with you, make sure it is over SSL.
In the past nobody much [that you were aware of] was watching your unencrypted activity and you may have been able to kid yourself that you could safely do the equivalent of hanging your house keys on the garden gate. We all need to wise up and be aware of what's public and what's private. That's all.