Sometimes a half-truth is worse than a lie
"T-Mobile Czech Republic managing director Milan Vašina says there was "no actual data leak" adding that "data are (sic) safe”. It is unclear if the company is claiming the records were for sale but remained not purchased."
I believe what the MD is saying here is that it wasn't a leak / hack and that their system is safe. Technically true, there was no leak and their system may be safe but they lost data because someone walked out the building with it.
To the (sic) comments above I would hazard a guess that use of "data" is in the context of "the data of our customers is safe" with an erroneous use of "are". Still, their English is likely to be better than a large portion of those who live in England and I'm referring to the native speaking lot before anyone accuses me of xenophobia.