What he said.
Absolute sacrilege - tea doesn't brew properly once the milk is added.
The fat in the milk clogs the pores in the Teabag if you are using them and/or otherwise coats the leaves so the water cannot act properly upon them. Either you wait for ages or end up with piss weak Tea. Putting milk in brewing Tea is....
"Well. I did almost think that it was time to pay them a visit but they seem to have being doing some terribly stupid stuff recently what with the...."
"My Lord!! We have reports of someone placing milk in brewing tea!"
"ARGGGGGH. Drop the Quarantine Buoy and get us out of here. Maximum Speed."