This week they did the same with another small but powerful broadband provider: Madasafish.
Madasafish is part of the Brightview group which also includes Global Internet, Waitrose Internet and the John Lewis ISP Greenbee. BT bought the whole lot this week for £15.8 million.
But in March of this year Brightview CEO David Laurie criticised a BBC Watchdog survey which put BT top in a survey of ISPs despite the fact that they had the third highest number of unhappy customers.
"As Britain's leading consumer affairs programme, it is Watchdog's duty to inform the consumer but... it only confused the issue," Laurie said.
"The BBC's ridiculous handling of the survey did nothing to reflect customer opinion and misled consumers into believing that a provider which achieved a customer satisfaction significantly below average is the best."
Plusnet have hardly been wilting violets on the benefits of consumers sticking with smaller ISPs either.
Are Madasafish and Plusnet contradicting themselves?
And should their customers be concerned at their change of heart?
Time to worry?
Since it was set up in 2001, Madasafish's excellent customer service and technical support have made the ISP well regarded by its 62,000 users and have won it several awards over the years.
Unsurprisingly, it's these qualities which some customers fear will be lost in the takeover.
However, Madasafish deny that there will be any degradation in speed or service.
"BT's investment means that we'll be able to extend an even greater product offering to our customers, whilst still maintaining the high level of customer service that Brightview ISPs are known for" claimed Samara Zittin from Madasafish customer services.
Since their takeover by BT, Plusnet have maintained their Sheffield based in house support team and, according to their latest report, "have no plans to outsource any of our support operations as the proximity of our support function to the rest of the business is fundamental to our business model."
Plusnet have even significantly improved their response times to support queries since the takeover.
See our full review of Plusnet for more on their customer service performance.
In addition, BT's general approach to takeovers tends to lend itself to quality over quantity.
Earlier this year they decided not to take over Pipex, an ISP with a larger customer base, after concerns about customer service.
All in all, though, there's little reason for customers to be too worried that the takeover will affect their service.
After all, months after their takeover, Plusnet's service is in itself not bad at all and we suspect Madasafish will be desperately trying to prove that the takeover has not affected their excellent customer service.
Only time will tell whether customers will see a difference.
Those within BT have their own takeover troubles.
The Rothschild bank advised BT about their Plusnet acquisition. Unfortunately, though, they didn't do a very good job of it.
Once a company acquires more than 30% of a company's voting stock it must also bid for the equity capital.
BT failed to make their bid because Rothschild didn't tell them about this rule and had to swiftly backtrack to get their share back under the 30% point.
We are independent of all of the products and services we compare.
We order our comparison tables by price or feature and never by referral revenue.
We donate at least 5% of our profits to charity, and we aim to be climate positive.
Get insider tips and the latest offers in our newsletter