Taras Khizhnyak, Senior Lawyer, BMS Law Firm:

Connecting to third party services without a subscriber’s consent may be regarded as tying in additional services which is against the applicable laws. Equally illegal is altering the source code of an Internet page which is subject to copyright protection. Regardless of website users and owners’ ability to decline such advertising, it is still illegal. Its posting requires consent of both subscribers and resources which source code is being modified.